How to increase file size limits and execution times

Add the following inside of a custom code snippet or a child theme:

@ini_set( 'upload_max_size' , '120M' );
@ini_set( 'post_max_size', '120M');
@ini_set( 'max_execution_time', '300' );

1. @ini_set( 'upload_max_size' , '120M' );: This line sets the maximum size of an uploaded file. In this case, it’s being set to 120 megabytes (120M). This affects the maximum size allowed for individual files uploaded through PHP forms, such as file upload fields in WordPress media uploader or other form submissions.
2. @ini_set( 'post_max_size', '120M');: This line sets the maximum size of POST data that PHP will accept. This includes form submissions and file uploads. It’s important to note that post_max_size should typically be larger than upload_max_size to accommodate the entire form submission, including any uploaded files. In this case, it’s also set to 120 megabytes (120M).
3. @ini_set( 'max_execution_time', '300' );: This line sets the maximum time in seconds that a script is allowed to run before it is terminated by the server. Here, it’s set to 300 seconds, or 5 minutes. This is useful for ensuring that long-running scripts, such as those performing complex operations or handling large amounts of data, have enough time to complete without being prematurely terminated.

Credits to WPBeginner for this solution