Sub domain not run, error 404

Hi everybody,
I am having a significant problem in creating subdomains by my phpscripts (I tried on cpanel, aapanel works).
My main domain is set to domain.com: in phpscripts, it will create a subdomain sub.domain.com but when created, it cannot run and gives a 404 error.
My DNS was pointed correctly and the CloudFlare connection was successful.

You can check for me at: https://my.iseo.website
Please help me use the trial package. Best regards!