Resend it to yourself.
Check junk and promotions folders first, and search for the event name.
If it is not there, use the Resend My Tickets page and enter the email address you bought with. The tickets are sent again to that address.
For security we give the same response whether or not the address has tickets, so make sure you use the exact address you bought with. If you bought with a different address and cannot remember which, contact support@meetmaker.com with the confirmation number.