Audio recorded in Iphone video camera.

I am trying to record video with my Iphone 7, and capture the audio from my UR44 conneced to the iphone via camera connection kit.
But since the loopback is not avalible in the Iphone version, I dont get any audio to my Iphone Video recorder.
Anyone tryed this, is there a soution?

I’m using an iPhone 7, they have recently done an update on the DSPmix FX app that happened automatically. So in the app the loop back function has changed to off/live cast /voice chat. I’m using livecast, the loopback is in the app not the phone.