You can build her confidence and social skills by getting her involved in group activities. Most people would agree that it's a lot easier to talk to strangers and turn them into friends when you're engaged in a fun or useful purpose together, rather than in the higher pressure small-talk situation where you have to come up with things to say.
The exact activity isn't really important, so much as the fact that your daughter likes it and is willing to weather the discomfort of learning to socialize in order to succeed or continue. Some possibilities are team sports, scouts, choir, dance or martial arts lessons.
You can also help her practice talking to peers by role-playing through conversations, giving her some sample icebreaking phrases to use with other kids, and offer her support and encouragement that she is a fun, likeable, interesting person.
I also want to mention that shyness is not an entirely bad characteristic, and it's possible that your desire to have her show a more outgoing personality, and the pressure of that, is part of why she struggles with video calls. Try to accept her own special personality, and realize that being shy is ok, and most shy people do learn to interact appropriately with others and have fulfilling social connections, even if they never become the life of the party.
Here's some more info about how to help shy kids thrive:
https://www.scarymommy.com/help-shy-tween-cope-school/
https://www.webmd.com/parenting/features/parent-shy-child#1
https://www.askdrsears.com/topics/parenting/child-rearing-and-development/8-ways-help-shy-child
https://www.psychologytoday.com/us/blog/growing-friendships/201606/helping-your-shy-child