PHP.ini file is a configuration file for the PHP server.
PHP.ini is generally created somewhere on the web server provider.
You can ask to have your administrator to create or edit a PHP.ini file in your own form if you want.
If you not know where is the php.ini file located. You can execute the phpinfo() function by uploading the file below.
Save it as phpinfo.php and upload to your Public_html folder.
Visit http://yoursite.com/phpinfo.php for example. then you will get like below.
register global variables, display errors, log errors, max uploading size setting.
Below are some commands for example.
upload_max_filesize = 1M.
post_max_size = 1M.
max_execution_time = 60.