How to record audacity playback

Hello,
I’ve found a way to create a kind of synth by looping a milliseconds long piece of audio (you can drag the loop to change the timbre and change its length to change the pitch) This has led to some interesting sounds that I would like to record via speaker loopback.

Problem is, it’s not possible to record audacity’s playback directly. I have found the feature which allows you to record while the existing audio plays, but it does not work with loops, it just plays the audio the whole way through.

This would rarely ever be done so I understand if it’s not possible. But do you think there is some way to do this, using audacity or with other program?