If you wish to install WordPress on your sub-domain, there will be changes on the Domain section as per the screenshot below: 

  1. Login tocPanel via yourdomain.com/cpanel
  2. Locate Softaculous Apps Installer
  3. Locate WordPress follow by Install 
  4. On the Choose Domain section, choose your desired sub-domain on the drop down menu

  1. The In Directory section should be blank or else the WordPress shall be install at sub.yourdomain.com/wp