Show QR Code on Order Confirmation Page

I tried adding this

$event = get_post($event_id);

$order = wc_get_order($order_id);

$registration_id = $registration->ID;

//buyer check

$buyer = get_post_meta($event->ID, ‘_attendee_information_type’, true);

$organizers = get_post_meta($event->ID, ‘_event_organizer_ids’, true);

$eventonline = get_post_meta($event->ID, ‘_event_online’, true);?>

and at the end

<img src=”<?php echo $qrcode_directory_new . ‘/’ . $event_id . ‘-‘ . $order_id . ‘-‘ . $registration_id; ?>.jpg”/>