Element (Matrix) client: setup hassle

Installed Element from flathub, started the program and got an error message:

Electron can’t find the key bundle, and something is wrong with gnome_libsecret. Encryption not posible.

You can either “cancel” which terminates Element, or “Continue with no encryption”.

I had to add org.freedesktop.secrets to the allowed Session Bus (used flatseal for that).