The Feenyx platform asks for access to your microphone and camera because the person that sent you your interview has required questions that include a video response. Some employers ask that you record a video to walk through your code, and others may ask non-technical questions much like a regular in-person interview.
If you're unable to access a laptop or computer that has a microphone and camera, you should reach out to your interviewer to let them know.
If you have access to a computer with the right hardware, you can test your hardware before the interview begins. Learn more about getting set up here.