How do I turn on mic and camera for Zoom?

I need to turn on my phone's mic and camera for appointment with doctor. Last time I was able to see and hear her on Zoom but she could neither see nor hear me. How do I enable my phone's camera and mic for Zoom?

 

Thank you ocnbrze and hadron. I was following remote directions/instructions on installing zoom so I didn't see all of its settings. I'll fix those settings for my next zoom appointment and see if that solves the issue.

I expect for security purposes I can remove the camera/audio permission between uses of zoom and them put them back on when needed.