According to https://support.mozilla.org/en-US/kb/how-set-firefox-sync-firefox-android, there should be a Sync and Save Date option in Firefox Android Menu, but it's nowehere to be found. I am using the current version of fire fox and am using the same smail on both devices. I tried using using the QR scanner from the dialogue box in the firefox keyboard, however that only brings up a "Did you use the system camera? You must pair from within the Firefox app." display. The option is still missing from the menu.