The license key for single user orders are usually included in your Order Confirmation email. Please open your order email and scroll down to about the second half of the email. You will see the license key included there.
For multi-licenses, there is a license generation and registration process, since these are specifically generated for the exact user amount purchased and registered in the end-user name directly. As soon as you complete your order our Licensing team will generate and register your license. You will then receive a second email with your License information.
If you still don't find your License key, please contact us here and we will be happy to assist you:
https://softwarecasa.freshdesk.com/support/home