After purchase product you will have a license key linked with that product. the license key will be mandatory for activate that product and keeping plugin up to date.
For activate the plugin from dashboard open up UNIM link menu like image in below
After activate plugin like describe in image you will have plugin’s update for one year.
This license key will be usable in single site, if you need change the domain or use the license on another domain, first deactive that in your first activated domain.