no Qt platform plugin could be initialized

[mvalenzisi]

After installing with pip install "openconnect-sso[full]" I get the following error:

$ openconnect-sso --server [REDACTED]
[info     ] Authenticating to VPN endpoint [openconnect_sso.app] address=[REDACTED] name=
[info     ] Response received              [openconnect_sso.authenticator] id=main message=Please complete the authentication process in the AnyConnect Login window. title=Login
qt.qpa.plugin: From 6.5.0, xcb-cursor0 or libxcb-cursor0 is needed to load the Qt xcb platform plugin.
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vkkhrdisplay, vnc, wayland-egl, wayland, xcb.

[warning  ] Connection terminated with browser [openconnect_sso.browser.browser]
[warning  ] Browser window terminated, exiting [openconnect_sso.app]

Any hint?