dspMixFx on iPhone + UR44: No loopback

I have a UR44 interface, an iPhone XS on iOS 13.4.1 and the Lightning to USB3 adapter.

I am planning to stream live with a guitar and mic and maybe record some videos on the phone.

On this video Dom Sigalas is using his iPhone and the UR44c to stream live on instagram. He turns on the loopback feature in order for the reverb to be heard on the stream.

When I try to do this I can’t, because that feature is not available on the iPhone.

This is a text from Steinberg page:

"Units need to be switched to class compliant mode to run with the iPad via the iPad Camera Connection Kit or the Lightning to USB Camera Adapter. In CC mode Loopback capability is disabled, and only the analog inputs and outputs are available on UR28M and UR824.

But, why is Dom able to turn on Loopback? I guess is because he is using the UR44C and the app is different. But he says that any UR unit can do what he is doing in the video. It is misleading. I just bought the lightning to usb adapter just because of that video.