mojave – MacBook Pro 2012 record audio from phone through aux in jack

I have a 2012 MacBook Pro 13″ and I need to record audio from Spotify playing on my phone into an audio track in GarageBand. (This is for a private, personal project, not any kind of pirating.) I just can’t get it to line up right.

I tried plugging the phone into the audio jack using just a standard 2-band stereo 1/8″ cable; that didn’t work. I then tried plugging it in using my detachable headphone cable (which has an inline microphone). That cable has 2-band on one end and 3-band on the other. When I plugged the 2-band side into the MacBook, the sound preferences showed “internal mic” as the only input option, and nothing was recorded. When I switched the direction, the sound preferences showed “external mic” as an option, but then it just recorded the audio through the cable’s inline mic, rather than the audio coming out of the headphone jack.

Would love for this to be possible… Any help is appreciated.