Online tutoring without a built-in microphone in the headset (student aid)?

Someone happens to be online tutoring here and can tell me whether it works without a mic. Because of the corona crisis, I have to do it now, I have no headset with built-in microphone and no laptop. Means - I have to do it on my 4.7 inch cell phone without a microphone and headset. Can you do that without a mic?

The cell phone has a microphone built in

I don't know if that's particularly good, but okay. I will try it.

But it's enough to make calls, right? 🙈

Of course, every cell phone has a built-in microphone!

You're right again 😂 was only surprised because it says that you need a headset with a microphone. But well. 😅 I could have figured it out myself, stupid question.