What method are you using? I trained our 25 month old at the beginning of lockdown using the Oh Crap! Book (it seems to be the popular one at the moment), the main method being naked from the waist down for the first few days, then introducing trousers, then introducing pants a few weeks later. He's very strong willed, got the concept straight away but we had major potty resistance.
I'm not sure backing off when you experience this resistance is a good idea - wouldn't that just teach them they get their nice familiar nappies back if they play up?
We used distraction, games, choices and "first, then" language to get over the refusal.
Distraction: specific books and toys that were only for the potty, "why don't you show (favourite toy) how you use the potty?", the odd YouTube video or TV episode while sitting. It's bribery to establish the habit and familiarity with doing something very new and strange basically.
Games: "Who's going to use the potty first - mummy or DS?" "(Favourite toy) wants to hear some wee wee!" "Mummy's going to close her eyes and listen for the wee wee!"
Choices: when in the first week he took against the potty, we also offered the big toilet with an adaptor on which worked for a while. When he started to refuse that, my other half managed to show him how to wee standing up (put him on the little step by the toilet and nudge DS's bottom forward with OH's knee to aim). Now he is comfortable using the big toilet when we're upstairs and the potty when we're downstairs.
"First, then": "DS first we're going to use the potty, then we're going to play outside." "First we're going to do a wee wee, then we're going to watch an episode of Thomas".
Now we've been at it a few months, accidents are very rare. He's just as likely to refuse to hold my hand or wash his hands before dinner as he is to refuse to sit on the potty - doesn't mean I'll allow him to do it, I deal with it in a similar way.