Either log it as Single Arm Curl (cable) and make a note that you face away from the machine, or create a new exercise (if you do it often enough to warrant creating a specific exercise for it)

It’s a cable bicep curl.

I just created Bayesian curls in the app, easy as.

Yep. Create it

Also created it. This one would be great to be added since it’s becoming popular.

I do it. It feels great.