I installed the Passwords app on the Iphone and set a password to access this Passwords app. I.e. when you open the Passwords app on the Iphone or you open the Passwords tab on top in your personal account in the browser, you must enter the password. And I forgot this password!!! How to restore it?
There is no reset function for the end to end encryption password. If you added the password recently you can check if the app still has an automatic backup from before you set the password.
Otherwise you can use the occ command to delete the data of the affected user account.
The question immediately arises: How do I save the files and then transfer them to a new account?
Are you still able to enter using another type of authentication? (e.g, fingerprint)? because if you do, try and search for this password among the list of normal ones. I think the app saves this password there when you first configure the app through the computer. [Edit: the name of the password is this: Passwords App Encryption Passphrase]
Otherwise, I think you’re out of luck. Even if you find the backup from the already encrypted database, you shouldn’t be able to restore it, otherwise, someone with access to your nextcloud would gain access to them, and the encryption is specifically designed for this.
In the case that you imported the passwords from another source (such as a browser), then delete everything from the passwords app and start from the beginning, importing again.
Sorry for bringing bad news.
The app also has the occ command
passwords:user:delete which deletes the data for the passwords app for the specified user.
By curiosity, I checked the backup files and they are JSON format but the passwords and other relevant data like usernames and URLs are totally encrypted.
Since autobackups are made daily by default, if @brava-net implemented the master-password only after the initial setup, they may be able to rollback to that point.