It is what it is.
I am just a user here, just like you.
I am sorry that these facts aren't what you want to find out.
I own an older iPad Pro and do a lot of creative, artistic endeavours with my iPad.
Music, being one of them, as well, and had to purchase some expensive external gear to record outside audio and do overdubbing through my iPad using a variety of different audio recording apps and specialised software sound modules
It's the way it is.
The iPad is NOT a fully dedicated/integrated recording studio.
External hardware is needed. Just like with any other type of audio recording methods.
Also, you never awarded me any points for my help.
You marked your own post reply as solved.