I forgot my password which allows me to unlocked my iPhone backup

You can’t restore an encrypted backup without its password. Here’s what to do:

1. Head to Settings > General > Reset.
2. Tap "Reset All Settings" and enter your passcode.
3. Follow the steps to reset your settings. This won't affect your user data or passwords, but it will reset settings like display brightness, Home screen layout, and wallpaper. It also removes your iTunes encrypted backup password.
4. Connect your device to iTunes again and create a new encrypted backup.

You won't be able to use previous encrypted backups, but you can use iTunes to back up your current data and set a new backup password.