Well, let me answer to you with 3 more questions:
If your answers were yes, yes and yes, then you have everything you need. Just go to the downloads section and grab the best option for you.
Well, the good news are that this awesome plugin is completely free for non-commercial use, but it has some limitations. If you need to use eProctoring services for large universities or more than 40 users per day then you will need the Premium version.
Please take a look at the pricing section to compare both versions and download the one that suit all your requirements.