Problem with Single Sign-On

I accessed https://chat.mozilla.org/ via Tor-network (Tor Browser with private window with Tor)

I created several Spaces and Rooms for my project.
Then I tried to add an email and Security Key.
But when I do this, I am asked to do a Single Sign-On in order to confirm the changes. When I agree, a window opens asking for my account email. But the System has no email saved yet.
“A client is trying to add a device signing key to your account. If you did not expect this, your account may be compromised!
Re-authenticate to confirm this acction.”

Is there a way to solve the problem?
Thank you.