I just tested it on my end. Admittedly the readme doesn’t explain how the module works very well.
Basically CV_1 is the volume of your incoming audio.
CV_2 is the volume of your loop.
Pressing the button toggles recording on and off. The first time you record a loop sets the loop’s length.
After that it will record new audio over top of the old (sound on sound).
Long pressing the button will clear the loop.
So to test the basic functionality of the patch you should:
patch some audio into IN_L and patch OUT_L to your speakers.
Set both top knobs to noon. Press and release the button, wait a bit, press and release again.
You should hear the looping audio playing alongside your currently running audio.
Hope that helps! Let me know if it still doesn’t work, we can try some other troubleshooting steps.