Citrix Receiver download.
Here is the offical how to guide.
The following command can be used to test for window manager support.
If there is no output, there is no support.
xprop -root | grep _NET_WM_FULLSCREEN_MONITORS
Further troubleshooting infos here.
In my case, I just had to launch the configuration manager and set it to “Full Screen”.
If needed, the resolutions settings can be found here: