Remove membership_id requirement on member import

my_pmproiucsv_modify_required_import_headers.php

<?php
/**
 * Remove membership_id requirement on member import.
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

function my_pmproiucsv_modify_required_import_headers( $required_fields ) {
	$required_fields = array_values( array_diff( $required_fields, array( 'membership_id' ) ) );

	return $required_fields;
}
add_filter( 'pmproiucsv_required_import_headers', 'my_pmproiucsv_modify_required_import_headers', 20 );