Cancel button on microsoft adaptive cards for teams

I am using the ms adaptive cards for teams using nodejs. I can see actions has button of type Action.Submit to pass form data. However, I want to understand how to handle cancel case.

Is there a way to simply close the form on clicking cancel button or I have to let it behave like save button and return nothing from server side when the cancel button is pressed.

my card is like below

{
    "type": "AdaptiveCard",
    "body": [
        {
            "type": "TextBlock",
            "size": "Medium",
            "weight": "Bolder",
            "text": "{title}"
        },
        {
            "type": "ColumnSet",
            "columns": [
                {
                    "type": "Column",
                    "items": [
                        {
                            "type": "Image",
                            "style": "Person",
                            "url": "{creator.profileImage}",
                            "size": "Small"
                        }
                    ],
                    "width": "auto"
                },
                {
                    "type": "Column",
                    "items": [
                        {
                            "type": "TextBlock",
                            "weight": "Bolder",
                            "text": "{creator.name}",
                            "wrap": true
                        },
                        {
                            "type": "TextBlock",
                            "spacing": "None",
                            "text": "Created {{DATE({createdUtc},SHORT)}}",
                            "isSubtle": true,
                            "wrap": true
                        }
                    ],
                    "width": "stretch"
                }
            ]
        }
    ],
    "actions": [
        {
            "type": "Action.ShowCard",
            "title": "Set due date",
            "card": {
                "type": "AdaptiveCard",
                "body": [

                    {
                        "type": "Input.Text",
                        "id": "comment",
                        "placeholder": "Add a comment",
                        "isMultiline": true
                    }
                ],
                "actions": [
                    {
                        "type": "Action.Submit",
                        "title": "OK"
                    },
                     {
                        "type": "Action.Submit",
                        "title": "Cancel"
                    }
                ],
                "$schema": "http://adaptivecards.io/schemas/adaptive-card.json"
            }
        }
    ],
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "version": "1.0"
}