open steamvr (can do this without using your vr) hit the three lines to open the settings, go to "workshop > upload new background" it'll open a dialog to upload your own stuff super easy.
the image you just make yourself in paint or photoshop or whatever. ideally make the resolution 8192x4096 and also basically ignore the top and bottom horizontal quarters as they get stretched to shit

Zappron is there some guide or instructions, or something, for those of us who want to try and make some backgrounds like this one if we have some source material that we can use or draw?

bad "art" where i go on my booru of choice and commit plagiarism because i have no talent (teehee)

what type of art is this

that would be amazing and i would be in your debt

could do 45

Ayyy UMP45 when?

based thk i added cuz i like gfl ig lel