Wassup bro.
I use an ipad 12.9 for music and video production.
I use a hub that has a usb type c Pd port. In my case, I then use my Arturia audiofuse interface as my main input. The usb connects to the usb interface on the hub. You can use any audio interface you would want I would imagine. Ive had this interface since they released it a couple years ago and ive used it across all the ipad pros without fault.