Applicable to - any servers (running PHP - CMS)
Rename index.php Because we are checking phpinfo() with index.php. So, rename server CMS provided index.php
$ mv index.php index.php.back
Create index.php file with phpinfo();
$ touch index.php
$ echo "<?php phpinfo(); ?>" > index.php
Now open the URL of your website, you will get to know - the php extensions loading with apache/nginx or whatever web-server you're using for web.
This is different from comman_line php.
For command line php simply check php -m | grep "extension-name"
or php -m
php -m. If you can upload a php file then usephpinfo()composer, then getcomposer.org/doc/01-basic-usage.md#platform-packages might help.