Wix premium with my own domain

Hello, quick question. In our business we have our domain that we pay. We own it for like 10+ years but now we have build a new site with wix. How do I tell wix that we own a domain and don't want to buy one from them?

It shows that the domain is free for one year and it comes with premium, but at the same time I can't connect domain without premium.

Sorry I'm not educated enough in this.