Apparently you didn’t. Please add your domain to your hosting account.
Note that you cannot add that domain directly to your account. You must add radzvpn.com first, then add that domain as a subdomain.
Which means this is simply not possible. Lying makes it harder to tell what’s the actual problem, so please always tell the truth, thank you.
After you added the domain, please change your Cloudflare SSL/TLS settings to Full instead of Full (Strict), the later doesn’t work on free hosting by default, is not recommended, and can also cause the “Host error”.