You have to have DNS hosting somewhere and a registered domain (at a registrar). DNS hosting is commonly provided by your registrar, but you are free to use other name servers to handle that part if you wish.
FastDomain.com provides for DNS service for domains where they are the registrar. Without you providing the current domain name, I can’t tell you who the registrar is nor what the current DNS records are.
If the domain registrar is fastdomain.com, you would follow the instructions at
to manage your DNS records.
The settings you would use for webflow hosting would be added as new / updated DNS records. Documentation is in the university.webflow.com site.
The only think you need to do with Wix, after you update your DNS records, and the site is running on webflow, is to terminate the hosting for that domain.