Need to transfer squarespace domain and the website is not letting me

I had a working website for a few years, and my domain must have expired. I bought the domain again grom google domains today. But when I try to connect it to my site it says it is being used by another squarespace site. The is what it looks like when I log in. The left is the domain I bought, the right is the site that used to work, but the domain expired. When I try to transfer the domin, it just takes me to the domain panel (image on the left) and then once I click the domain I want to transfer, it prompts me to sign up for a domain email...

how do I transfer it. I did not mean to buy the domain to be on a different site like this. Just meant to buy the domain like how I did the first time 

When I try to connect the domain to the site on the right,I get this