A single Google Workspace with multiple websites and different emails

Hello! I noticed in my Google Workspace account (activated/purchased through SquareSpace) that I could add another domain. Purchased a new domain in SS, and connected all the links, but when I went to activate a new email in Workspace, Google said I needed to purchase another license through my third party provider. 
Now that you have context:

If I purchase another Google Workspace license will it be a completely new instance of Google Workspace or can I manage it from my "first?" And is there an add-on purchase option or is it always the same flat price? 

Thanks! 

Steve

I know we're in the middle of a pandemic...again, but even a yes, you always have to purchase a new instance, or yes you can do an add-on. Alternately: No, you are insane! Aieee!

Cheers!

Hi Steve,

I don't have an answer for you because I have the same question. I have multiple domains and want all of the emails to be managed under one Google Workspace account. I will keep you post if I figure anything out.

D. Brown 

Has a response or resolution been posted for this topic yet? I just purchased two domains last night and want different emails from original (third domain) with Google Workspace.