1.20.1 I have tried setting up a auto composter and the basic hopper will not work with a vanilla composter. I have seen tutorial videos that show this so it did work at one time but it doesn't anymore.

I am traveling but I tried like a normal hopper first small end into the composter. Then I read online to put it into the side for some reason so I tried that. Then I gave up and put your hopper into a vanilla hopper Into the composter.

Vanilla hoppers only work from the top, and I am not sure if his are the same or if they can even be used in this way. They take from inventories and im not sure if they can connect to other inventories the way a normal hopper can.

the mod's hopper seems to work differently when placing it differently.
show us screenshots of your setup

I am traveling but I tried like a normal hopper first small end into the composter. Then I read online to put it into the side for some reason so I tried that. Then I gave up and put your hopper into a vanilla hopper Into the composter.

Vanilla composters only work with vanilla hoppers on 1.20, It's a limitation in Forge's capability system. It should work on 1.21+ NeoForge and Fabric.