input_block_only.json

{
    "type": "input",
    "block_id": "fake_block_id",
    "label": {
        "type": "plain_text",
        "text": "Label",
        "emoji": true
    },
    "element": {
        "type": "plain_text_input",
        "action_id": "action"
    },
    "hint": {
        "type": "plain_text",
        "text": "Hint",
        "emoji": true
    },
    "optional": true
}