iphone x: please help me add microphone to apps such as zoom and teams. Not finding option under the app, privacy or mic setting.

If you attempt to use a mic in an app, it should prompt you to turn it on in Settings>Privacy>Microphone. The app should appear in that list after you have attempted to use the microphone. The app will not appear in that list unless you have tried to use the microphone first. They do not appear there until that time. The app should automatically generate a popup asking permission. If it doesn't, force closed the app and they try opening it again and trying to use the microphone. How to force an app to close on your iPhone, iPad, or iPod touch - Apple Support