You can install all Among Us mods in the same way, you just have to download their build.
The tutorial you see below works for Steam and Epic Games.
Go to the release section, find the latest release, and download the .zip you see among the files. On the picture, you see an example.
Your Among Us folder is located where you installed Among Us. It is at C:\Program Files or C:\Program Files (x86) by default.
Your Among Us folder should look similar to the one you see on the picture after extracting the .zip. It may not be perfectly the same, but the BepInEx and the dotnet/mono folder, and the doorstop_config.ini file should definitely be there, otherwise, you have done something wrong.
Note: More files and folders will appear after the first launch of the game after you have completed the installation.
If the installation is successful, you will see the mod version at the top of your screen when Among Us has loaded in.
Note: It may take a while to open at the first launch since the game has to create all the files and folders mentioned in the previous step.