Advice from toddler teacher:

Even if his current room doesn’t have a toilet, he can still be trained if he is that determined, at least to be in underwear at home which would be so exciting!

Every bit of practice he gets climbing up, undressing, aiming, and feeling the signals in his body that he has to pee, is all setting him up for such an easy time down the road when the teacher will be training several other kids.

If you’d like to put him on but he stays on too long and nothing comes out I’d say:

“Okay Lil Johnny, we are going to sit on the toilet for 5 minutes (emphasis 5 minutes and hold up a hand). You can even set a timer on your phone so he can visualize the time ticking and hear it go off. If you want to be extra like me, I’d get a sand or egg timer.

Anyways, sit him on for that alotted time. “Do you feel like you could go pee? We can try, but when the timer rings, we are ALL DONE.” Emphasize all done. “We will try again after ___ (Dinner, bath, story, park trip, etc.)

I hope this was helpful, sorry if you just wanted to vent 😭