Install the license
After your registration you will find a free trial license in your dashboard. Copy the license number.
Inside the plugin dashboard press the button on the top-left corner with the logo. Will show you a new sidebar menu. Select the License menu.
Will open a popup. Paste the license number and press activate. The license will be attached to your domain, but you can deactivate the license and activate in another WordPress installation.
In your account in alexreservations.com you can also view the domains that you have activated for each license and even disable it from there.
You can manage different licenses for different WordPress sites. And inside each WordPress you can manage one or several restaurants depending on your plan.