How do we find who to contact for the website host?

I'm trying to help my brother update his website, and I'm not sure who is hosting it. A few years ago my brother paid someone to build him a website. He thought it was hosted either through Wix or vistaprint. This is the web address: https://www.glasermotiongolf.com/

I did a whois lookup and I get this info Name Server: NS8.WIXDNS.NET Name Server: NS9.WIXDNS.NET

When we login to Wix, under "My Sites" it says "Create Your First Site" which makes me think he has not set up anything with them. He also does not have any billing history with them. When we login to VistaPrint, it shows he has paid them annually for a few years. However, I don't see anything related to his website. Who do we contact, or what should we do to find out this information?