Here’s a guide on how to install PHP extensions
Log in to your DirectAdmin panel by adding ':2222' to your website URL. It should look like this: 'yourwebsite.com:2222'.
Scroll down to Extra Features.
Click on Select PHP Version.
To install an extension, for example, mysqli:
Scroll down until you find the letter M.
First, deselect nd_mysqli and then select mysqli.
If you encounter any issues, feel free to reach out via Discord or create a support ticket through this link.