Boot into OpenPHT fullscreen

Hey,
I'm running OpenPHT on a Debian server, that I use as a media and file server and some other stuff.
I'm wondering if there is a possibility to have it set up in a way, that when I boot up the server it automatically opens OpenPHT in fullscreen.
What I tried was, to create a new user that would automatically login after boot and using the GNOME Tweak Tool I set OpenPHT to auto launch. This works fine, except for the fact that after opening OpenPHT I still see the Gnome menu at the top of the screen. And I have to use a mouse to click into the window that OpenPHT is running in to get it to disappear.
Now, ideally I would like not to have any peripherals like mouse or keyboard connected to the server, because it will be standing in my living room. So OpenPHT should open smoothly on its own.
I was wondering about, if it would be possible to have the Debian user account set up in a way that on login it only opens the essential tools for OpenPHT to run. Maybe something like a kiosk mode, so that the over all experience would be similar to using Rasplex.