Potty training toddler refusing nap

My 2 1/2 year old recently mastered daytime potty training, only now she’s always got to ‘go’ when she lays down for a nap. I don’t want to discourage her from going when she needs to, but this is an hour and a half of laying down and then getting up because she has to go (which she obviously doesn’t). My fear is that the one time I tell her not to get out of bed, I’ll be forcing an accident. Thoughts or tricks? This is day of three of this and yesterday she was so tired she fell asleep on the couch and had a little accident. How do I encourage her to use the potty when she needs to but still get her to take a nap?