You need to register your Parallels Desktop for Mac Business Edition license before using it for activation.

When you start Parallels Desktop for Mac, click on Business Edition.

Enter your activation key (dashes will be added automatically).

Once you enter the key, it will be validated. If the key has been successfully validated, click Activate.

If your Mac is connected to the Internet, Parallels Desktop for Mac Business Edition will be activated.

Note: You can simplify the activation process by inviting users to install Parallels Desktop via My Account. Learn more in KB 124428.