How to get Action.OpenUrl working?

[aubreyquinn]

I am using the sample from the adaptive cards web site: https://adaptivecards.io/explorer/Action.OpenUrl.html

{
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "type": "AdaptiveCard",
    "version": "1.5",
    "body": [
        {
            "type": "TextBlock",
            "text": "Click the cat!",
            "weight": "bolder"
        },
        {
            "type": "Image",
            "url": "https://adaptivecards.io/content/cats/1.png",
            "altText": "Cat",
            "selectAction": {
                "type": "Action.OpenUrl",
                "tooltip": "cool link",
                "url": "https://www.youtube.com/watch?v=dQw4w9WgXcQ"
            }
        }
    ]
}

What I am expecting to happen, is to open a new tab in the browser with the url provided. What's actually happening is a popup/alert dialog is opening instead.

What am I doing wrong?