You're probably most familiar with the USB-C to female 3.5mm adapter ... But you can also get something like this JMOX USB-C to 3.5mm Audio Aux Jack Cable, which ends in the protruding, male ...

In a sense, even the cheap, $10 dongle that converts your phone's USB-C port into a 3.5mm jack is an audio interface. However, when most people in the know think of an audio interface, they ...