I really want to second dxh's answer, as I feel it's by far the best in this case. If your child has regularly handled video chats in the past without issue then I suspect the problem is not the video chat themselves. I suspect the covid-19 and quarantine is hard for her, the change of her normal, what's expected, and who she can visit can be confusing and upsetting to her. She doesn't know how to handle this new status quo.
The video chat's are likely seen as a replacement for in person meetings, and as a symbol/representation of how things have changed since covid-19 has started. What she is really saying is she doesn't like being quarantined from those she loves, but she lacks the ability to communicate this properly.
She isn't alone in this regard, My oldest goddaughter is having the exact same experience at the moment. She did video-based activities at first, but as the quarantine continued she started to refuse to do her gym and language classes over video, which she liked at first, as it started to get frustrated with what she was missing and wanting to rebel against it. She felt like doing these activities meant giving up on the way things use to be, and in general was frustrated with the changes and lacked any other good way to handle them.
The only difference is since my goddaughter is a little older, and a child who will never be accused of being afraid to express what she wants quite clearly, she was a bit better able to articulate her feelings. When asked if she wants to video chat with me her response was always the same, "No, I want Drew to come here". In her mind if she refused my video chats enough eventually she would finally get me to come visit again.
To answer your specific questions, I don't think this is about preferences for how to communicate, every child at 2 prefers face to face contact over video chat; but usually they don't refuse video chat options, just like your daughter use to enjoy them. Further more if a child doesn't like video chat they just ignore it, the fact that she is actively screaming and fighting it shows an emotional aversion far stronger then just preference to face to face communication.
I do think this is a phase, specifically one caused by covid-19, but that doesn't mean you should ignore her emotions.
Dhx already talked a good bit about how to help her to express her feelings about video chat, I won't repeat what he said other then to say I agree with it. I would go a step further and try talking to her about her feelings about covid-19 and the quarantine as well. Is she only upset about not getting to see people in person, or are her feelings a part of a larger distress over the entire change for her environment and lifestyle caused by covid-19?
Try to give her a chance to express, as much as she can, how she feels about these changes. Listen to her and make sure to validate her feelings. Tell her you understand it can be upsetting and your very sorry that things had to change. Ensure her that things won't stay the way they are now, but at the same time let her know that it's okay that she is upset about the change and it's okay to not like how things are now, ie just because it won't stay like this forever doesn't mean her feelings at the moment aren't just as valid. It can help to tell her how you feel about the changes, that you miss her grand parents too etc. Let her know her grandparents are missing her just as much as she misses them (but not in a way that makes her feel guilty for not video chatting with them, she doesn't need more stress!)
I would also consider not doing the in-car visits right now, or at least giving her a choice about them. If she is only going to get upset that she can't play with her grandparents when you do your drive by visits then it can be far more upsetting to her then not doing the visits at all. I'd let her decide which she wants to do and make sure she knows that either option is okay to make.
Still, you wanted to do video chats, so lets see what we can do to make them happen. With my goddaughter the way we arranged them was by having me not call her. Specifically her mother would tell her that I was calling my youngest god daughter, instead of the oldest that didn't want to do video chats, and that she didn't have to participate in them if she didn't want to. Of course once I was on the screen and her younger sister happily playing with me the oldest sister was quick to jump in and participate in the calls as well.
You could try something similar by telling your daughter that your going to call your grandparents because you want to talk to them. Talk to her ahead of time to tell her your missing your grandparents and so are planning to call them later today. don't ask her to participate, in fact tell her your get out her coloring books or otherwise give her some activity she can do while your chatting (to make it more obvious that this is your call time and not hers since you arranged other activities for her). You an tell her she is welcome to talk to them if she wants to, but she doesn't have to.
Ideally she will not see this as a problem since she it isn't a video chat for her in place of personal visit time, but it's hard to say how she will view this. That's why I suggest mentioning your plan ahead of time and seeing how she responds to it.
Assuming she isn't too vehement about resisting you I would set her up with an activity and call them from another room. Then wander in to the room a little later while talking to them and stay conspicuously close. Don't insist that she participate with them, just be nearby with her grandparents on video chat. I suspect that, much like with my goddaughter, once you have them on video chat without upsetting her she will be quick to wander over and join in on the call. The important thing is to make sure she doesn't feel like she is being forced to, let her join in without being reminded that she was resisting the video calls.
If she shows distress over this as well then as I said validate her feelings by acknowledging she is upset and letting her know your do something about it. Either leave the room again or get off the call so you can show you are respecting her enough to try to avoid upsetting her.
Only mildly related, but once you have her willing to do video chats there are many things you can do to help get her more active in them. I've found kids work best with video chats when you can engage them in more then just talk. As already suggested reading a book can sometimes work, but at 2 a more active game works best. Some games I've found work well with toddlers for video chat:
Ring around the Rosie, both sides spin around, and fall down, together. If your parents aren't up to the physical exertion required to constantly 'fall down' you can usually tilt the phone/tablet your doing the chat in the air instead, as long as someone goes out of frame the kids don't usually ask too many questions on how it happened.
Singing, especially songs that involve hand motions or dances as part of the songs. For instance the Ittsy Bitsy Spider and Skidamarink have some pretty common hand motions associated with them you can do while singing the song. Here is a whole list of 'action songs' you can do with kids.
Peak a boo. turn the camera a little to put you out of frame, then come back in frame to surprise a kid. Mix it up by coming in from different angles/sides of the camera, or put your finger right on the video camera to black it out then remove the finger etc (works better with younger kids obviously)
'eating' together. Have a similar snack on both sides of the camera that you can share. Include games of pretending to eat the toddlers food. Ask them to 'feed' you by holding their snack up to the camera and pretending to eat it, then let them do the same with yours etc. Kids really love feeding you on camera....
Hide and seek: This works best, obviously, with a parent there to 'assist' in the game. Have the kid hide and you carry the phone/tablet used for video chat around as her grandparents are 'looking' for her, then you hide the tablet somewhere and have your daughter find it, while grandparents talk to the child to help her to find them. Oddly enough kids really enjoy playing hide and seek even if there isn't someone around to help the person on the other end of the video chat seek them. You would think that wouldn't be a very effective game, but all the kids I've done it with still somehow enjoy it; kids are strange ;)
"faces" as my nephew calls it. Most phones and tablets out there come with tools to mess with your video feed, things like turning your face into a dogs or having rainbows rain out of your mouth when you open it, they have all kind of bizarre features. If your using a a video device that already has these features kids love seeing what strange faces you can turn in, and will usually be happy to make games out of some of the sillier ones. You can install software to add more options like this as well if you (or your parents) happen to be willing to put in the effort to do so.
Simon says. This one is pretty self explanatory, just play the game :P
The biggest thing with video chatting with young children though is to be a little over the top. Be extra loud, extra excited, just a bit more dynamic then in person to help keep them engaged.