How can i determine which websites are associated with licenses

I have bought quite a few licenses for the same theme (The 7). I beleive some of the websites are no longer online. However, I am not certain which websites were using The 7 Theme. How can i determine which websites are using the license? If the website is offline, how can i delicense that website? I hope this makes sense.
Thanks
Danny

Too many similar request/posts on the forum. You can just search for more suggestions.