Whatsapp stuck on preparing backup

Hey guys, I want to restore my daughter’s XR from the new device and not from iCloud backup.
The only app I need to backup is whatsapp, but it is almost impossible to do that from the app. There is a lot of space in the phone, a lot of iCloud space but the process got stuck on the Backup Setting step.

No way.

After some tutorials I tried to run the WA backup after canceling the icloud backup with no success.

I’m thinking of buying trans software for mobile, even if that kind of thing doesn’t give me any confidence at all.

Any suggestion would be appreciated.