A question to people who have done battery swaps - do you need to erase-restore an iPhone beforehand for the process, or you just give it to the repairers as is? If the latter, do they ask you for a passcode?
I did it twice in my life and I didn’t erase the device before doing. Don’t give your passcode to ANYONE, Apple included.
I don’t know about third parties repairers.
For sure it is recommended to have a backup before doing that, but a backup is recommended anyway