Following the video worked for me, and hopefully this helps someone else as well. I had to do this several times as there were multiple programs stopping D3DOverrider from opening. For me, the culprits were Discord, NVIDIA Broadcaster and one or two others I kinda just glossed over and spammed until D3D started working and opening.
What to do if it does not appear in the tray (3 comments)
See this video
It should probably work.