3.5 year old won't stay dry...

Thanks for any thoughts and well wishes in advance.

First a little context: I am late to the potty training game. When my kiddo was about 1.5/2 I ended up in hospital with a life threatening illness that left me disabled and in a ton of untreated pain. Now that I am finally doing better and our lives have mostly settled we have started potty training.

Kiddo is a very independent person, prefering to learn on their own as opposed to instruction and actively fights any offer for assistance. They also struggle with transitions despite adequate warning (think from car to shop, or house to car, or in this case playing to potty).

We've had a lot of success with potty training using a small reward of chocolate upon peeing and pooping in the potty. Here's what we have accomplished:

• always poops on potty
• pees on potty everytime set on potty
• will occasionally use potty unprompted (mostly if they have to poop)

Here is what I'm struggling with.

• kiddo fights wearing underwear despite finding diapers uncomfortable and not wanting to wear them. I suspect this is partly because they struggle to put it on themselves and their underwear is my biggest indicator that they are wet.

And my greatest woe...

• Always wetting themselves and having to be forced to go to the potty as opposed to communicating their need to go, or going independently when they need to go. They never ever stay dry.

I feel like if they could communicate when they had to go, they would feel more in control and we would have more success. Any advice on how to help them would be greatly appreciated.