The title says recovery key and your question body mentions recovery key. The former is to get access to the Sync data in case you lost the password and the latter is if you use two factor authentication and lost access the the authenticator app on the mobile phone. If you can access the Firefox Account then you can probably generate a new recovery key via the settings page. To generate new recovery codes you would have to disable 2FA and re-enable 2FA (i.e. setup 2FA). *https://support.mozilla.org/en-US/kb/secure-firefox-account-two-step-authentication *https://support.mozilla.org/en-US/kb/what-if-im-locked-out-two-step-authentication See also: *https://support.mozilla.org/en-US/kb/reset-your-firefox-account-password-recovery-keys