How to create a carousel for FB Messenger in Dialogflow using API results? (the amount of returned results is variable)

Question

I have access to the Movie Database API, which I want to use the data from to create a carousel in Facebook Messenger via DialogFlow. However I'm quite new to the Custom Payload in Dialogflow.

When I open it it shows:

{
  "facebook": {
    "attachment": {
      "payload": {},
      "type": ""
    }
  }
}

I tried some templates like How to create a Facebook Carousel in Dialogflow as "Custom Payload" and it worked.

Here is some example data that the API returns. In the example, the data contains 3 movies.

    {
        "popularity": 1149.646,
        "vote_count": 51,
        "video": false,
        "poster_path": "/9Rj8l6gElLpRL7Kj17iZhrT5Zuw.jpg",
        "id": 734309,
        "adult": false,
        "backdrop_path": "/7fvdg211A2L0mHddvzyArRuRalp.jpg",
        "original_language": "en",
        "original_title": "Santana",
        "genre_ids": [
            28
        ],
        "title": "Santana",
        "vote_average": 5.7,
        "overview": "Twee agenten, twee broers. De een is uit op gerechtigheid, de ander op wraak. Ze kunnen elkaar vermoorden voordat ze de slechteriken vangen.",
        "release_date": "2020-08-28"
    },
    {
        "popularity": 966.368,
        "vote_count": 191,
        "video": false,
        "poster_path": "/uOw5JD8IlD546feZ6oxbIjvN66P.jpg",
        "id": 718444,
        "adult": false,
        "backdrop_path": "/x4UkhIQuHIJyeeOTdcbZ3t3gBSa.jpg",
        "original_language": "en",
        "original_title": "Rogue",
        "genre_ids": [
            28
        ],
        "title": "Rogue",
        "vote_average": 5.9,
        "overview": "Door de strijd geharde O'Hara leidt een levendig huurlingenteam van soldaten op een gewaagde missie: gijzelaars redden van hun ontvoerders in afgelegen Afrika. Maar terwijl de missie mislukt en het team strandt, moet het team van O'Hara een bloederige, brute ontmoeting met een bende rebellen tegemoet treden.",
        "release_date": "2020-08-20"
    },
    {
        "popularity": 893.987,
        "vote_count": 420,
        "video": false,
        "poster_path": "/ew1lAU8yV66JbivBU1Zh4Wj4pOB.jpg",
        "id": 581392,
        "adult": false,
        "backdrop_path": "/gEjNlhZhyHeto6Fy5wWy5Uk3A9D.jpg",
        "original_language": "ko",
        "original_title": "반도",
        "genre_ids": [
            28,
            27,
            53
        ],
        "title": "반도",
        "vote_average": 7.1,
        "overview": "",
        "release_date": "2020-07-15"
    }
];

How can I make a carousel with 3 cards (containing the title, image and a button that sends the overview) in the Custom Payload in Dialogflow?