I tried a few threads already on Blender Stack Exchange:
I'm using 'Images as Background' add-on. I've tried the 'Film' 'Transparent' recommendation. The render icon is on in the outliner. I've messed with the nodes all day. Nothing seems to be working.
I made an animation in 2.79, and I opened the file in 2.83,(I checked the box to not load the UI thing) so maybe a few bugs from the old one got into the this file because I tried loading up a new 2.83 file and the background rendered just fine with no modifications.
I am using HitFilm 3 Express as my video editing program, I am more comfortable with it than Blender's internal video editing software. So I'm rendering out a greenscreen for the program to use.