Worked great
We flew from Kunming China to Phnom Penh Cambodia on Thai Airways and to board the plane you need proof of departure from Cambodia; we don’t have a set schedule so we didn’t want to commit to a departure date and destination so we used Onward Ticket two hours before our flight and was instantly issued a ticket. When we arrived at the airport to check in, the ticket agent asked for proof of departure from Cambodia, I showed her the ticket that I downloaded from the email from Onward Ticket, she typed in the flight information into her computer and we were issued our boarding pass! Worked perfect