You have to activate the theme license key before installing the required plugins.
Go to (Solustrid > Product Registration)
Please follow the below process step by step to activate the license.
1. First, put your license key in the License key blank field.
If you can't find the license key then this article is for you.
2. Checked the box on the left side of the consent description.
3. Click on the Activate License button.
You will see the License Activated notification on the top like this below. Thats means Congratulation! Your license is successfully activated.
4. Click Save Changes Button
If you face license activation problem, please contact our support system by following this link https://support.smartdatasoft.com/