Hi there,
Thanks for writing in! You can validate your staging domain (maybe a subdomain?) for now. When you are done with that and ready to move to your live domain then just revoke the API Key for the staging domain and validate the live site. So you don’t need to purchase separate license for this.
But if you need to run both seamlessly then you need to purchase separate license for the staging domain.
Hope this helps.
Cheers!