Follow these steps :
1. Log in to your cPanel.
2. Scroll down to the Software/Services category.
3. Locate Softaculous and click-open it.
4. Click on MediaWiki under Wikis in the left navigation.
5. Click on the Install tab at the top of the pane.
6. If your site carries SSL certification, choose HTTPS as protocol.
7. Select the domain name where you want to install it.
8. Enter a Directory and Database Name.
9. Enter a Wiki Name and Wiki Email.
10. Enter an Admin Name and Admin password.
11. Click the Install button.
Done!!
