Applies tags to users when order is placed On Hold (cheque payments)

wpf-apply-tags-order-hold.php

<?php

// Applies tags to users when order is placed On Hold (cheque payments)

add_action( 'woocommerce_order_status_on-hold', 'custom_wpf_woo_on_hold' );

function custom_wpf_woo_on_hold( $order_id ) {

	$order = new WC_Order( $order_id );
	$user = get_user_by( 'email', $order->billing_email );

	// Change 123 to the tag ID to be applied
	wp_fusion()->user->apply_tags(array(123), $user->ID);

}