Use headphone jack as input
I have a new Macbook Pro 13" 2019 w/ four thunderbolt 3 ports. I am trying to use the headphone jack as an input to record music into programs such as GarageBand and Audacity. However, there is no option in the sound settings to use the port as the input. It only shows the built-in microphone as a possible choice for the input. My instrument is plugged in properly to the computer. Can anyone assist me please and thank you?
MacBook Pro with Touch Bar