Hi Irene,
Unfortunately the MediaRecorder element is mostly supported by Firefox desktop and Chrome desktop only for now. I’m not sure what are the capacities of Chrome on iOS, whether there are any OS-wide limitations
I know it’s technically feasible to record audio streams in a browser from an iPhone, but developers seem to use a different API than MediaRecorder. I know I should work on implementing alternatives in the future, but it’s not a priority at the moment
Unless you are willing to code your own voice-recording system, I’m afraid you’ll have to tell your iPhone participants to use a computer indeed, I’m sorry
Jeremy