regular license - how do I correctly link the client to envato license?

This may be a stupid question, but I do not want to have troubles.
I bougt a plug-in for a wordpress site and want to sell the site to a client. I know that I have to have a license for each client and that I have to , but how do I correcrtly manage the “link to the envato license”.

Thank you very much for your help!

@Camenzindus I ran into a very similar problem… I ended up with what seemed like hundreds of plug-ins and themes that required me to keep track of who “technically” owns what. I wanted to make sure that I was not using a clients purchased license on another clients website and keeping tabs on all of it started out easy. Now that nearly every author forces the use of the actual license key to be tied to a specific customer for updates I ended up making a spreadsheet containing key information like client name, purchase date, associated website and license keys with their appropriate download link. In the future I intend to create an app to do it for me on a smaller scale than many of these IT management tools, but until then a spreadsheet seems to work best.