Hi derek53,
Under Settings, Media. Once you activate the plugin, the settings for Prizm Image will show up on that page, and there will be a section with a box next to it that says:
WP Prizm Image
Enter your Prizm Image License Key. In order to use Prizm Image, you need to register for a free License Key. You can get your License Key here: http://www.prizmimage.com/Home/Login
Enter your free code into that box. We use currently use these to track to make sure individual users aren’t abusing the server, getting stuck, etc. In the future, we are considering charging in the future when you get above some yet to be determined amount of images, but we will give ample notice to existing users (and maybe early bird discounts, so sign up now 🙂
As you may have guessed, I work for Accusoft, the publishers of Prizm Image.
Best regards,
Tom