How can I record video with mixer audio on my iPhone?

I want to record video taking direct audio from the mixer in a live event so that visuals and audio could be captured perfectly. I was using an android device earlier, there was a 3rd party apps ecosystem that provides the same facility. We can record the video just like DSLR/ Camcoders etc.

Tried to connect with Apple support - the team is in denial mode for that.

There may be some 3rd party apps available for the same in AppStore, if someone could assist me, I'll be grateful.

Regards,

Sudhir