Include approval status in the Members List export CSV

my_pmpro_members_list_csv_approval_column.php

<?php // copy from below
/**
 * Include membership approval status in the Members List export CSV
 * 
 * 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_pmpro_members_list_csv_approval_column( $columns ) {
	$columns["approval"] = "my_pmpro_members_list_column_approval";
	return $columns;
}
add_filter( 'pmpro_members_list_csv_extra_columns', 'my_pmpro_members_list_csv_approval_column' );

function my_pmpro_members_list_column_approval( $user ) {
	if ( ! class_exists( 'PMPro_Approvals' ) ) {
		return;
	}

	$approval_status = PMPro_Approvals::getUserApprovalStatus( $user->ID, $user->membership_id );
	if ( $approval_status !== NULL ) {
		return ucfirst( $approval_status );
	} else {
		// The member existed before Approval was required
		return '-';
	}
}