Follow the link provided in your exam reminder email. For most learners, your connection link will be https://proctoring.offsec.com/student/login. Enter only the numeric portion of your OSID and enter your full md5 value. Please note that if you attempt to join too early, you might not be able to connect, as proctors will only be available 15 minutes before your scheduled exam start time.
Note: For in-depth instructions, please take a look at the Proctoring Tool Manual.