Max Upload Size means how much the size of the largest file’s size can be.
The upload_max_filesize can be set by modifying multiple files. They are .htaccess, php.ini, .user.ini, or wp-config.php. files. You are gonna need FTP access to modify those files. You can find the credentials for your FTP access from your hosting provider.
To set upload_max_filesize please follow the steps given below,
1.Go to your WordPress root installation folder and locate any of these files .htaccess, php.ini, .user.ini or wp-config.php
2.Select any of the files above and Edit and paste the code given below,
3.Save the file.
php_value upload_max_filesize 32M
for php.ini or .user.ini
@ini_set( 'upload_max_size' , '32M' );
The recommended time is ’32M’ minimum.