How can I purchase a sealed flight route from Bangkok to Phuket?

Users are discussing how to purchase sealed flights from Bangkok to Phuket, which are part of the Phuket Sandbox initiative. A user shared that these flights can only be booked on a single ticket as part of a connection from an international inbound flight to Bangkok. They won't show up when searching directly for Bangkok to Phuket. Travel agents may be able to assist in booking these flights.