section_block_fields.json

{
    "type": "section",
    "block_id": "fake_block_id",
    "text": {
        "type": "mrkdwn",
        "text": "Test:"
    },
    "fields": [
        {
            "type": "plain_text",
            "text": "foo"
        },
        {
            "type": "mrkdwn",
            "text": "bar"
        }
    ]
}