Use for Highend theme

Hello, I have purchased and use Highend theme and I love it.

I will be creating two more websites in the future.
Is it OK to use the downloaded highend theme for them? Or is the downloaded theme only to be used for one website?

Am I allowed to use the downloaded highness theme for more than one website if I pay for the additional cost? If so, where do I pay for it?

Thank you.