Hi

First check your sync options in your browser, type this in the address bar -> about:preferences#sync Just check if everything is checked. Then go to your phone and check the setting too, make sure that he is connected to internet.

Go to firefox in the menu and press Sync button

https://support.cdn.mozilla.net/media/uploads/gallery/images/2014-03-21-11-47-32-4281dc.png

You can't view Sync data on a different device. And you can't view Sync data which is on the Sync server.