After purchasing a license for Smart Shooter 3, you will receive an email containing the license key information. This email is sent to the same email address that you specified when making the purchase.
The license email contains the license key both in the text of the email, and also stored in a file attached to the email. The screenshot below shows an example of the license email, with the license key text highlighted in yellow.
When Smart Shooter 3 is started, it will show the following window. Click the Register button.
The Registration window, as shown below, is where you can enter your license key. So, copy the license key text from you email, and then paste it into the box here.
Once the license has been checked and verified, you will see the confirmation as shown below. Details about your license and purchase will be shown in the Registration window.
If you ever need to return to the Registration window, you can click the menu item as shown below: