如何通过Slack API回复用户DM？

import requests

def reply_to_dm(api_token, channel_id, message):
    url = 'https://slack.com/api/chat.postMessage'
    headers = {
        'Authorization': f'Bearer {api_token}',
        'Content-Type': 'application/json'
    }
    data = {
        'channel': channel_id,
        'text': message
    }
    response = requests.post(url, headers=headers, json=data)
    response_data = response.json()
    return response_data

# 使用示例
api_token = 'your_api_token'
channel_id = 'user_dm_channel_id'
message = 'Hello, this is a reply to your DM!'
response = reply_to_dm(api_token, channel_id, message)
print(response)