Domains are hard. Sometimes when you think you've set everything up, you find out there are more issues. We hate how hard they are, and will be happy to help as much as we can.
To get this working:
Log into the dashboard where you bought your domain (GoDaddy, Google Domains, etc...)
Go to DNS settings
Look to see if there is a record with type A and hostname @. If there is, edit that one. If not, add a new one. Use the following info:
IP Address: 188.8.131.52
TTL: Default or 15 minutes.