Try to reset the Firefox Sync password to see if that gives access to the account and disable two factor authentication. You may have to try this more than once to be able to disable 2FA (i.e. use a fresh login). In case of issues try to log in to the Firefox account via this website. *https://accounts.firefox.com/signin *https://accounts.firefox.com/settings *[/questions/1226620] I forget recovery and security code *https://support.mozilla.org/en-US/kb/secure-firefox-account-two-step-authentication