I have created a subdomain but I can not access it, I have to use Cloudflare
If you are using third party nameservers, you are responsible for making use the DNS records are correct. That means that, if you create subdomains, you’re responsible for setting up the appropriate DNS records as well.
If you don’t know how to manage your own DNS records, please switch your domain name back to our nameservers, which we can automatically configure for you to have the right DNS records.
Also, as I know, subdomains doesn’t work with Cloudflare integration panel in vPanel.