Flacon failed to start


I installed Flacon on Debian 11 but when try to start, it says the following error. Any help to fix this please.

xxx@penguin:~$ flatpak run com.github.Flacon
Start flacon 11.3.0
Warning: could not connect to display
Could not load the Qt platform plugin “xcb” in “” even though it was found.
Error: 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, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, xcb.

Just let me add.

I use Linux on Chromebook using ARM Cortex-A78 Kompanio 1200.

Does this cause this error??

Pls advise what I try to fix.