Well, I had to do some digging through the Documentation Center to accrete insight. And I ultimately found it in the Documentation for FormFunction under scope/controls in this example:
CloudDeploy[
FormFunction[{"x" -> <|"Interpreter" -> "String",
"Control" ->
Function[
Tooltip[InputField[##],
EntityValue[Entity["Species", "Species:FelisCatus"],
EntityProperty["Species", "Image"]]]]|>}, func]]
Since there's an explicit InputField there I just had to use this example as a hint for the answer I gave you.
