Tap on the project name at the top of the screen when you are in Record mode. Then tap "Disabled" to the right of "Metronome" below settings. This will pull up the Metronome screen. From there, tap the yellow slider to enable the metronome.
You can then adjust the time signature and tempo. Short taps will increase the tempo by +/- 5. Long taps by +/- 1. Once you set the metronome, tap "Done" at the bottom of the screen, then 'Done" in the upper right of the screen.
When you start recording you'll hear the click track, so use wired headphones or AirPods to record. You can silence the metronome off and on with the yellow icon in the upper right of the record screen.
