If you have purchased a SQL Backup Manager upgrade license, you can enter it via the License Management window.
To begin, click the License management tool link in the Tools and utilities tab of the main application window.
The license management tool shows your current license type and key (if any), as well as an expiration date (if you're using a trial license).
Enter a new license key, copy and paste it into the New License field, then click the Save button.
If you've installed an upgrade license, you will also find options for copying the current SQL Backup Master license key to the Windows clipboard, or to remove the current license from the installed application instance (which will revert it to the features of the free edition).