curl --location --request GET 'https://slack.com/api/chat.scheduledMessages.list'{
    "ok": true,
    "response_metadata": {
        "next_cursor": ""
    },
    "scheduled_messages": [
        {
            "channel_id": "C1H9RESGL",
            "date_created": 1551891734,
            "id": 1298393284,
            "post_at": 1551991428,
            "text": "Here's a message for you in the future"
        }
    ]
}