Option "Call using internet audio" not showing on iPhone

[Picali]

TL;DR:  is "call using internet audio" not possible on iOS without Wifi connection? 

I'm trying to host a zoom meeting from my iPhone using the Zoom iOS app. I have a Pro account. When I'm connected on the T-Mobile LTE network I can do video just fine, but the option "Call using internet audio" doesn't appear.

When I set up the meeting to only use Device audio, starting the meeting I just get the options "Wifi" or "No audio". When I set up the meeting to also allow Telephone Audio, starting the meeting I get the options "Wifi", "Dial in" or "No audio", but still no "Call using internet audio".

Once I enable Wifi I can join with device audio, but the location where I will be hosting the call doesn't have Wifi. Did I miss a setting somewhere, or is this simply a limitation of the Zoom iOS app?

[Picali]

Replying to myself here, this looks like it is a UI bug. Zoom did have access to Cellular data (iOS settings > Zoom > Cellular data, see screenshot), but never offered using it for audio. Turns out, when connected over LTE but NOT on wifi, it would offer "Wifi" as an audio option. Tapping that, audio does get recorded. And related: in Zoom settings > meetings > auto connect audio, there is no mention of cellular data at all (see other screenshot), so it just seems like the app incorrectly assumes that it cannot use the cell network for audio. That makes for a very confusing user experience. Glad it's solved for me. Seems like it's not widespread, so I wonder what's so special about my iPhone 12 mini, Zoom app, or zoom account settings.