AS far as I can see from plugin page you should've received your license key with your purchase. Have you already installed the add-on in your JIRA instance? Check on page below>Installation tab:
If you are not able to retrieve your license you can write directly to J-TRICKS that developed the add-on at firstname.lastname@example.org
Did you also send the details via the license page? If not, please do that or I am sure some one will reach out to you requesting the details.
Once you get the license, upload it in the plugin configuration page, as mentioned by Thiago.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs