new licence

Hi, I'm using <h3 class="t-heading -size-xs">Aether Content Hider Plugin for WordPress</h3> in one of my websites, but now I have tryed to us it in another one,  because it is working perctly for my needs. I have copied the plugin in the new installation but obviuslly it is asking me to purchase a new licence. Can I use the same purchase code for it or I have to purchase a second licence? If I have to purchase a second licence, how can I get it on the evanto market? Thanks in advance Matteo M.