Gravity forms set featured image using Standard and Advanced fields through URL to attachment conversion

url_to_attachment.php

<?php

add_action( 'gform_after_submission', 'upload_photo', 10, 2 );
function convert_to_attachment( $entry, $form ) {

	// ID of the title field
	$title = rgar( $entry, 1 );

	// ID of the upload button 
	$url = rgar( $entry, 2 ); 

	$args = array(
		'post_title' => $title,
		'post_type' => 'photo'	// Custom Post Type
	);

	$post_id = wp_insert_post( $args );

	// Current directory
	$abs_path = getcwd();

	// Convert to absolute URL
	$url = str_replace( site_url(), $abs_path, $url);

	// Checking filetype for MIME
	$filetype = wp_check_filetype( basename( $url ), null );

	// WordPress upload directory	
	$wp_upload_dir = wp_upload_dir();	

	$attachment = array(
		'guid'           => $wp_upload_dir['url'] . '/' . basename( $url ), 
		'post_mime_type' => $filetype['type'],
		'post_title'     => preg_replace( '/\.[^.]+$/', '', basename( $url ) ),
		'post_content'   => '',
		'post_status'    => 'inherit'
	);

	// Get attachment ID
	$attach_id = wp_insert_attachment( $attachment, $url, $post_id );

	// Dependency for wp_generate_attachment_metadata().
	require_once( ABSPATH . 'wp-admin/includes/image.php' );

	// Generate metadata for image attachment.
	$attach_data = wp_generate_attachment_metadata( $attach_id, $url );
	wp_update_attachment_metadata( $attach_id, $attach_data );

	// Set as featured image for the post created on line 13.
	set_post_thumbnail( $post_id, $attach_id );
}

Thank you!