Flathub specific instructions?

I tried, but I have no idea what is really necessary to use OpenRGB within Flatpak. I have a keyboard that is supposed to work, but it never shows up; are there any Flatpak specific things that I should know before using this application?

The issue names no file, test, or entry point; begin by checking how OpenRGB is packaged and what Flatpak-specific setup the application requires for keyboard access. Done means documenting the required steps and confirming that a supported keyboard appears when those steps are followed.

Written by the indexing model from the issue text.