Need help giving member access to only 1 site in workspace

Hello all, I am struggling to figure out a solution here. I currently have just hired a designer for a new project. I have a 2 seat freelancer workspace in Webflow. I want this designer to work on only this one website, and not have access to my other sites.

I am not sure how to set this permissions in the platform, and I don’t want to create a separate Webflow account yet for my client because then they would have to pay for hosting before the site is even completed.

Can anyone assist here? Surely it should be simple, but perhaps I am overlooking it. Thank you!