My son was daytime dry at about 2 years, he was 5 or 6 before he was nighttime dry.
Just use pull up nappies.

There is some hormone that gets released to wake you up in the night, that doesn't come in at the same time for everybody.

https://www.nytone.com/blogs/bedwetting-resources/9172029-primary-bedwetting-cause-low-antidiuretic-hormone

> **How LAH Causes Bedwetting** 
>
>The antidiuretic hormone is made by nerves
> in the hypothalamus part of the brain. It helps control blood
> pressure, and regulate fluid volume in the body by passing it out
> through urine.
> 
> In children under 9 years old, it is very common for little brains to
> produce a low level of this antidiuretic hormone at night. If your
> child has LAH, when they go to sleep, since the levels of the hormone
> drop, and the brain does not inform the bladder that it is full. In
> essence, the bladder overflows without waking your child. This is how
> LAH becomes a bedwetting cause in children under 9.