The phpinfo.php file is not included in generic installs of WordPress on Sitegroud. It is a helpful file for determining your server information. It is easy to create one. All you need to do is:
- Go to your file manager and create a file named phpinfo.php inside the public_html folder
- Put this line of code in the file: <?php phpinfo(); ?>
- Thats it.
See Siteground documentation for more information.