Am wondering just how severe the crease is. Here's my experiement with a crease:
Having rescued the heart chain off
eBay that went to Chanel spa to redye, it still has a crease running the entire length right under the turnlock. After doing some research, I found that one can try using a hot iron on STEAM setting to lessen a crease in leather. I did not put the iron on the hottest setting and as a precaution I put a washcloth between the leather and the steam. While the leather was still hot, I tried to keep the leather taut and left it cool. I repeated the process several times. After steaming I stuffed the purse to keep the leather stretched. Look for something round. Tissue paper won't work.
The crease is still there. It's certainly no worse than before I started.
That said the article I read was about someone who had folded leather that was going to recover a car interior. The advice was to steam the leather and let it drape over a circular bar so the crease would drop out. The steaming process with the purse is more difficult because you can't take that portion with the crease and hang it til it dries.
I think it's worth the effort if the crease isn't severe. There was no discoloration to the leather. DO NOT place the iron on the leather but rather hold it above the crease and let the steam heat the leather. Until you are comfortable that it's not going to hurt your purse, use a slightly damp section of washcloth between the leather and the iron. After about my 4th attempt and the purse was doing fine, I just held the iron just above the leather.