Have you finished the whole Intro to Vet Tech?
Do you have a webcam and microphone on your computer/laptop?
Do you know if you have all the required apps/software up to date?
Check out these other discussions regarding the Remote Proctor Exams:
Remote Proctor PC requirements - some software you may need. if you don't have these or don't have the newest update, this may be causing you not to be able to take the exam