Help with Apple Shortcuts "Data" formatting

Hi, I’d like a Shortcut to announce typed text via my Alexa Media notification service. It works in the Developer tools UI in HA but I don’t know how to format the “data” field within Apple Shortcuts. I know from the documentation that there’s a Dictionary way of doing things, but what do I do when there’s indented formatting?

How do I get this:

data:
  message: The fridge door has been left open
  data:
    type: tts

into the Shortcut app

I tried a YAML to JSON converters to get this:

{
    "data": {
        "message": "The fridge door has been left open",
        "data": {
            "type": "announce"
        }
    }
}

but when I paste that into the field in Shortcuts app, I get “The operation took too long to complete, please try again” in the app, OR it looks like it successfully concludes but doesn’t actually do anything.
Please help, thanks!