This article provides a detailed explanation of each setting found in Schema → Settings → Licenses.

Schema Premium License Key
Enter the license key you received when you purchased Schema Premium, and click Save Changes. This will ensure you receive automatic plugin updates and allow us to provide support for you more swiftly should you need it.
If you’ve purchases and installed any extensions for Schema Premium plugin from our site, you will new field for each extension. If your license key has expired, please renew your license.