How to license a Discoure.PRO plugin for an intranet?

We are looking to by Image gallery plugin.
I see that there is need to provide url of discource instance to proceed check out.
My discource is on private addres and restircetd domain.
Will I be able to install plugin on private site ?
My discource has access to intenet but, acces from internet to my discource is resticted.

Thanx in advanced

Yes, please specify the «intranet» string in the «Your Discourse site URL» field.