Hi Steven By "Mozilla phone", I am guessing you mean Firefox for Android, as Firefox OS devices have not been supported for six years. Firefox for Android does not support primary password - the code to access saved user credentials is the same as your device unlock code. With regards to primary password in Firefox on a Windows computer, this support article should help: https://support.mozilla.org/en-US/kb/use-primary-password-protect-stored-logins#:~:text=Create%20a%20Primary%20Password,-By%20default%2C%20Firefox&text=to%20open%20the%20menu%20panel,the%20Logins%20and%20Passwords%20section.