Product Key was used by student

We are using the Engineering Kit in our classroom. The kits were registered under student accounts through Arduino.

Now the teaching staff doesn't have access to the accounts associated with the product keys. For various reasons, not all the students are available to give us access.

My first question is if there is a way for us to reclaim the product key number to regain access?

Secondly, looking forward, what is the best way for an instructor to set up product key that allows us to retain access and give access as needed?