Your PHP installation appears to be missing the MySQL extension which is required by WordPress

Symptoms

You see the following message when loading your WordPress site:

Your PHP installation appears to be missing the MySQL extension which is required by WordPress

Description 

This issue can happen due to a number of causes such as not having the extension installed in Easy Apache. You can install the extension with the following steps:

1. Login to WHM as thee root user

2. Navigate to: Home »Software »EasyApache 4

3. Click the blue Customize button

4. Click on the PHP Extensions button in the left sidebar

5. Type mysql into the search bar

6. Enable the mysqlnd extension

7. Click the Review button in the left sidebar

8. Click the blue Provision button

If the extension is already installed, check the following articles for other possible causes:

1. If the PHP version is set to Inherit in cPanel's MultiPHP Manager, it is possible that the CloudLinux PHP Selector could be in use, but the MySQL extension is disabled in PHP Selector. If this happens check to ensure that the MySQL extension is enabled in PHP Selector, or change the PHP version to something other than Inherit in cPanel's MultiPHP Manager.

2. Missing MySQL Extension due to suPHP configuration issue

3. Missing MySQL Extension due to the use of Alt-PHP from Imunify360