Applies to all interfaces
In this example, we are using the Scarlett 2i2 2nd Gen interface.
1) Connect your interface and open Audacity
2) Ensure 'Core Audio' is selected and the interface has been set as the Input and Output device.
3) If you want to record using just the first input of your interface, select '1 (Mono) Recording Channels'. If you want to record a stereo source (i.e. inputs 1&2), you will need to select '2 (Stereo) Recording Channels'.
4) Click the record button in Audacity. The project will automatically start recording. Click the 'Stop' button to stop the recording. You can then play the recorded audio back by clicking the 'Play' button.
If, after the above, you still cannot see an audio signal, please see this article: