Follow the below steps to Save and Activate the license key:
1. Go to Order Delivery Date -> Activate License option as shown below:
Order Delivery Date -> Activate License option
2. On this page, you will find the Plugin License Options. Now in the License Key field, enter the license key provided in the email.
Activate License Page
3. Now click on Save Changes and then on Activate License button. The status will be changed to ACTIVE and will be shown in green next to the Deactivate License button.