Could you say more please? Did you do this yourself? Apple replacement? local repair shop? Costs? I've never owned a battery-operated device long enough to worry about battery replacement. That said, given that Apple now disdains the smaller form-factors of the iPhone13mini, battery replacement will become a need at some point.
I have replaced iPhone batteries myself but prefer to have Apple do it. The one time that Apple could not unstick the battery, I received a refurbished iPhone in its place.
Years ago when I bought a 6S, I mentioned to the Apple employee that I had replaced batteries on the 5 series myself, but they had all swollen. On the down low he said, “They all do that, but ours do it less.”
When my wife goes to the USA to visit her kids, she takes one or two iPhones with tired batteries, drops them off, and picks them up before she returns. I make the appointments online beforehand with a note saying that she’s on a visit from abroad and needs it done quickly, and it’s never been a problem.