1. Log into your cPanel account.

2. In the Domains section, click on the Domains icon.

3. Enter your sub-domain name under the Domain field and select Just use "test.primarydomain.com". (primarydomain.com  should be your actual domain name.)

If you want to create a sub-domain for an addon domain, then enter test.addondomain. (addondomain should be your actual domain name). You need to specify the addon domain name folder after  /public_html/ field.

Leave all fields as they are autofill.

Uncheck " Share document root (/home/username/public_html) with . " if it is checked.

4. Click on the Submit button.