video_block_basic.json

{
    "type": "video",
    "block_id": "b1",
    "alt_text": "alt",
    "thumbnail_url": "https://example.com/t.png",
    "title": {
        "type": "plain_text",
        "text": "Title"
    },
    "video_url": "https://example.com/v.mp4"
}