Reply To: appointments plugin

[Support teamKeymaster]

Use this plugin Notification — Custom Notifications and Alerts for WordPress with the next code in functions.php:

add_filter( 'notification/settings/triggers/valid_post_types', function( $post_types ) {
    $post_types[] = get_post_type_object( 'booked_appointments' );
    return $post_types;
}, 10 ,2 );

This will be add Appointments to custom post types.