To create a subdomain in DirectAdmin, please follow these steps:
1. Log in to your DirectAdmin control panel.
2. Click on the "Account Manager" icon, and then select "Subdomain Management."
3. Click on the "Add Subdomain" button.
4. Enter the desired name for your subdomain (for example, "newsub.sitedemo.com").
5. Click on the "Add Subdomain" button again to complete the process.
Please note that it may take up to 10 minutes for a new subdomain to become active. Once the subdomain is active, you can begin using it to host content on your website.