A subdomain is an additional part of your primary domain. For example, blog.example.com is a subdomain. Please, follow this tutorial to create a subdomain in cPanel.

1. Log in to your cPanel account.

2. In the Domains section, click on Domains.

3. Click on Create A New Domain.

4. Under the Create a New Domain, enter the following details:

• Domain: Enter your main domain name. This is the base for your subdomain.
• Share document root: Must uncheck it to create your subdomain.
• Subdomain: It fills up automatically. Remove the domain extension (like .com or .net).
• Leave all other options as it is.

5. Click on Submit.

You should see a success message that the subdomain has been created.