How can I open 'audacity' in GarageBand?

Thank you. I don't know what is happening but I should be getting a call from Focusrite tomorrow. I now get signals for my instruments and voice but it will not record anything in GarageBand. It shows the Scarlett so it's not that it doesn't recognize the interface. Something else is going on and I just don't know what it is. I have read article after article and wasted more hours than I care to think about. Hopefully this guy from Focusrite can help me. Thanks a bunch, have a great night.

I did that already and the mic is on for my Mac. I don't know whether I should see GarageBand in the microphone section or not but if I am supposed to see it, GarageBand is not in the microphone section, it does also show Zoom.

Thank you. Well if I have GarageBand do I not really need audacity? I am not sure what is happening and I cannot record. Do you know, do I have to have audacity to record on GarageBand?