Send 'invoice' email notification when user is added using Add Member Admin Add on.

pmproama_send_invoice.php

<?php


// Add this function to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
function pmproama_send_invoice( $user_id ) {
	$order = new MemberOrder();
	$order->getLastMemberOrder( $user_id );

	$pmproemail = new PMProEmail();
	$pmproemail->sendInvoiceEmail( get_userdata( $user_id ), $order );
}
add_action( 'pmpro_add_member_added', 'pmproama_send_invoice' );