Using the `igp_image_filename` filter in Instagrate Pro

igp_image_filename.php

<?php

add_filter( 'igp_image_filename', 'my_igp_image_filename', 10, 4 );
function my_igp_image_filename( $file_name, $file, $post_name, $postid ) {
	$file_name_parts = explode( '.', $file_name );
	$ext = array_pop( $file_name_parts );

	$file_name = 'my-prefix-' . implode( '.', $file_name_parts ) . '-'. date( 'Y-m-d' ) . '.' . $ext;
	
	return $file_name;
}