Potty training with speech delay

[Teeny6]

Hello. My twin boys are 3. They have speech delay so aren't really able to verbally communicate but do understand. I'm struggling with potty training. They can't really tell me when they need to go and wgwh the do pee their pants they don't seem to mind being wet. Any hints/tips appreciated

Do they use gestures or signing at all? If they do, could you really emphasise a clear sign for toilet, either the official one or something you've made up? Or a picture/small toy toilet they could give you to show they need the toilet, but that adds finding it as an extra step.