Just checked, and the Betfury site is opening for me. So the problem is probably on your side.
You can try to access the site from a different browser or device. Also, if you use Chrome, you should find the security tab in the settings and check the "Use secure DNS" option. If you have "With your current service provider" selected there, then change it to custom by selecting Google or some other.
If that doesn't help, you can also try to clear the DNS cache via cmd with the ipconfig /flushdns command.