For my org's upcoming fundraiser we want event ticket purchasers to print and bring a copy of their tickets as verification they paid. I need the autoresponse email for either the RSVP confirmation or donation receipt to have the following fields:

• Event ticket name (regular or vip)
• Number of tickets purchased

I've seen liquid available for these elements ({{ event_ticket_level.number }}), but I cannot get it working in either autoresponse. How do I get this working?