When capturing videos with your smartphone, sometimes you want to record with an external microphone, even if your phone's built-in microphone is good. This is because the built-in microphone sometimes has issues when recording certain types of videos or audio.

When this happens, you can try using the Camera External Mic (CEM) app. This app lets you record video and audio using your phone's camera and an external microphone, and then it lets you use the resulting video and audio as if you were recording with the phone's built-in microphone.

To record videos using the CEM app, you will need to allow the app to access the phone's camera and microphone. You will also need to allow the app to access external storage.

After that, you will be able to start recording videos. To do that, you will need to click the Record button in the app's menu.