How to take toddler boy potty in public?

M • 💙 Our blessing arrived 08/18/2017 💙 Baby boy #2 arrived 11/14/2019!

EVERY single place we go my son needs to go potty as soon as we enter the front doors 😂 My husband will take him and hold him up over the urinal, and he will grunt and get frustrated, only actually peeing about 1/4 of the time. What else can we do to make him more comfortable since he can't yet reach the potty on his own? He won't sit - wants to be just like daddy and has always stood to pee.