How to unregister license from a site that is unreachable

Hi,

How can I unregister a site that used the AAM license key but that site has been moved to another URL? In this case the site is essense.eu.testbyte.nl (which was
the test URL). But the site is not there anymore (and impossible to set up there again), it moved to production and is using another instance of the license key.

https://www.ads-software.com/plugins/advanced-access-manager/