The CNAME domain name generated by WAF or Anti-DDoS Pro is used for DNS resolution and cannot be directly accessed.
If you access the CNAME directly, a 504 error page may occur.
If you do not want to switch DNS to test the WAF or Anti-DDoS Pro configuration, see Modify hosts file to test Web Application Firewall.
If you adopt an architecture with the combination of CDN and WAF, you only need to change the source site on the CDN configuration page to the CNAME domain name provided by WAF. Do not change the back-to-source host in the CDN configuration.