You can modify the content and appearance of error pages on your site, such as 404, 403, 500 errors, etc.

1. Log in to your control panel (cPanel).
2. Click on "Error Pages" from Advanced section.
   
   
   
   
3. Select the page you want to modify by clicking on it.
   
   
   
   
4. Write the content you want to add or HTML code. After completing the desired modification, click "Save".