You should receive your license key in a separate email when you purchase Calypso. Altogether there will be three emails:Order confirmation emailCalypso download link emailLicense key emailYour license key is a string of numbers and letters that looks like this: vvvvv-wwwww-xxxxx-yyyyy-zzzzz. When you run Calypso for the first time, you will need to cut and paste this license key into the pop-up window in order to activate your license.If you purchase Calypso and do not receive a license key, or if you lose your license key, contact Calypso Customer Support at info@calypso.software for assistance.