If your WordPress site is not opening and you are getting “Your PHP installation appears to be missing the MySQL extension which is required by WordPress” error whenever you are trying to access the site, do these:
- Upgrade to latest WordPress
- Change php version of your site to 7.0
To update your WordPress, login to your site cPanel and use the softaculous wordpress manager to get it done.
You can change the PHP version of your site via cPanel >> MultiPHP Manager >> Choose PHP version.
NB: If your change php version to 7.3, you might still get the error. So, try 7.0. it should work but ensure you upgrade your wordpress to the latest version.
useful resource : How to Fix WordPress Error Missing MySQL Extension Problem