where can I find my back up encryption password?

If you have a Mac computer then you can check to see if it exists in the Keychain Access app. Search for iPhone Backup and see if has a password saved there. If not then you will have to keep guessing at that password. You get unlimited tries.

Axel F.

If you are creating an encrypted backup file (Which you are) then your computer will ask you to setup a backup file password. You can then use that password so that the backup file can be restored to your iPhone. I think that your computer is asking you to set up a password for the encrypted backup that you are creating.

Axel F.

You are welcome and Good Luck.

Axel F.