There was no casting service built into the TV. The only option was Samsung Smartview, and streaming from a PC.
The TVs in other DVC rooms (and elsewhere on property, such as Coronado) have chrome cast built into the TV and don’t require an external device. You navigate to the correct channel, activate casting, and the TV now appears on the Wi-Fi network as a device that can be casted to.
Because these TVs have DirectTV with over the air channels and not an interactive guide connected via Ethernet, the ability to cast directly to the TV was missing.