I have license key of remote utility and I would like to apply license key on admin and all users AD automatic have license key as well.
Starting version 18.104.22.168 you only have to apply the license key on the Viewer side. You do not have to register remote Hosts. Here is a registration tutorial.
Nowadays, when I apply license key on Viewers on admin and I also have to apply license key on users AD too.
You have an outdated version then. Please, update your Viewers and Hosts and try to register the Viewer again. If you can't , feel free to submit a ticket with your license key to us. Please, do not post your license key on the forum.