1] To do this, change the upload_max_filesize and post_max_size directives in your php.ini file.
To ensure that file uploads work correctly, the post_max_size directive should be a little larger than the upload_max_filesize. For example, the following settings demonstrate how to set a file upload limit to 20 megabytes:
upload_max_filesize = 20M
post_max_size = 21M
2] You need to add the following codes at the bottom of the .htaccess file:
php_value upload_max_filesize 128M
php_value post_max_size 128M
php_value max_execution_time 300
php_value max_input_time 300
ref links: https://kinsta.com/blog/wordpress-maximum-upload-file-size/
https://kinsta.com/blog/wordpress-maximum-upload-file-size/