Backup will not auto or manual backup on iPhone 11

Already spent 2 hours on phone with Apple support. They sent me to a Apple person in London drugs. He said phone diagnostics is good. Feels it is a software issue. Only resolve is to totally reset the phone. The auto backups have never failed until Dec 2021. As I do not have a laptop, only a iPad to do a backup b4 totally resetting the phone I thought I would see if anyone had this happen.