reset encryption password

This support article will tell you how to reset your password for future backups.

About encrypted backups on your iPhone, iPad, or iPod touch - Apple Support

You won't be able to use previous backups unless you can figure out your password.

From what I understand though, if you are trying to restore from an encrypted backup.. there is no restriction on your guesses to try and figure out that password. So try your commonly used passwords?

There's no reset for encrypted password.

If you cannot remember the password, you cannot restore from the encrypted backup.

FYI, You can still do backup without the password but to restore you need the password.

you can't do it.

this is what it's meant to be, since otherwise anyone who got an access to your backup can reset password and get your sensitive info