Firefox for Android and laverna

Hi, a few months ago I gave laverna a try and now came back to it to make it work with a RemoteStorage again. But unfortunately i forgot my passoword.
Now, thats not bad because it just was a test i did.
None of the notes are relevant.
So i wold like to set up laverna again but i can’t because the browser somehow stored the device name or something that identicates my mobile android phone. And always shows me the login of my first connection.
I tryed several things and then I tryed on Firefox for windows and found that in the settings i had to delete a line in security - saved passwords called laverna. Then i was able to make a new account.
But how can i do that on firefox for android? I don’t find that. I tryed to delete all kind of private data but without success…

The password for laverna is unfortunately not stored there…
In the meantime i found that the cloud software “cozy” has a remotestorage integrated and i managed to use that one…
Regards, Novski