What kind of DAC do I need to do both USB C Midi in and aux audio out?

I want to send MIDI from my Circuit Tracks to my iPad by USB C and send audio back to the Circuit Tracks but the iPad only has a USB C port. Could someone point me to a cable that can do this? I tried 2 different USB C / aux splitters but they don’t work. I was told I needed something with a DAC but can’t find the type of cable online that sounds like it’s the right one.