add field to bookings-event-printable.php

Hello,
I have to add some information in printable booking. I have some ticket with different times of booking, and I set this in BOOKINGTICKETNAME and in BOOKINGTICKETDESCRIPTION.

I edited the file booking-event-printable.php and put it in wp-content/themes/Your Theme/plugins/events-manager/templates/bookings-event-printable.php but i don’t know how set the php file to show BOOKINGTICKETNAME and BOOKINGTICKETDESCRIPTION.

I write this, but doesn’t work:

<td><?php echo $EM_Booking->booking_ticket_name ?></td>
<td><?php echo $EM_Booking->booking_ticket_description ?></td>