CaesarLooper is a SuperCollider clone of the Augustus Loop VST plugin by Expert Sleepers.
In order for it to work you need SuperCollider:
https://supercollider.github.io/
I recommend the latest version.
IBufWr:
https://github.com/tremblap/IBufWr
Once you have this working:
Quarks.install("https://github.com/X2theL/CaesarLooper.git")