Before you troubleshoot, please see this article on how to allow camera and microphone access on the student portal. Also, please see this article to see what browsers and devices are supported.
Camera and Microphone Access on Apple Devices
Step 1: Navigate to the Settings app.
Step 2: Scroll down to Privacy & Security.
Step 3: Select Microphone.
Step 4: Select Extempore.
Step 5: Repeat for Camera.
Camera and Microphone Access on Android Devices
Step 1: On your device, open the main Settings app.
Step 2: Tap Apps or Application Manager (depending on your device, this may look different).
Step 3: Tap on Extempore.
Step 4: Tap Permissions.
Step 5: Turn permissions on.