If you mean the old-style bi-fold screen door, it’s a standard aluminum frame with screen material held in a groove with a lock strip. You might be able to remove a little bit more of the lock strip, stretch it back into position, and press the lock strip back in place without removing the door. An extra pair of hands would be very helpful.
Failing that, you’ll have to remove the whole door. I think you have to take apart some of the wood frame at the top to get the roller track loose, but I can’t remember for sure without looking at it. Mine is out of pocket at the moment.
If you mean the newer Plisse sliding screen, I haven’t a clue. The manufacturer might be able to help, though between the pandemic and the holidays, I don’t know what their customer service department is like.