If the camera and microphone access do not work after troubleshooting your browser, there are a few steps to check on your Mac to ensure that Flipgrid has access to the device's camera and microphone.

Troubleshooting Macs for Camera/Microphone Access 

Check Mac system settings 

1. On your Mac, choose Apple menu > System Preferences, click Security & Privacy, then click Privacy
2. Select Camera
3. Select the tickbox next to an app to allow it to access the camera. Deselect the tickbox to turn off access for that app.
4. Follow the same process for your microphone

If you don't see the Camera/Microphone setting in the Privacy section, please update your Mac OS to the latest version - https://support.apple.com/en-gb/guide/mac-help/mchlpx1065/mac

If you have multiple audio devices connected to your Mac, it may not select the one you are trying to use. Here's how you can change those settings:

1. Open your System Preferences
2. Click on "Sound"
3. Click the "Input" option
4. Here you will see a list of your audio input devices - select the device you are wanting to use.