How can we change the Cpanel max upload size?

You can change upload_max_size via a several ways.

Solution 1: cPnale INI editor
cpanel -> software and services -> Select PHP Version -> Options

Solution 2: using .htaccess way
You can get .htaccess file from root folder of your website. Mostly it’s hidden. So using FTP makes sense. Or you have to open your file manager with hidden files.
If there is no .htaccess file, create and upload/paste in root (before creating .htaccess file, make sure there is no .htaccess file). Paste the following code,

php_value upload_max_filesize 1024M
php_value post_max_size 1024M
php_value max_execution_time 1000
php_value max_input_time 1000

Solution 3: PHP.INI file method
You can find your php.ini file in root folder. Sometime you can’t find there. No problem, just create one php.ini file and paste/upload in your root folder with following code. If already file is there, just add this code,

upload_max_filesize = 1024M
post_max_size = 1024M
max_execution_time = 1000