[Slack] send message

• https://api.slack.com/methods/chat.postMessage
• https://slack.com/api/chat.postMessage

Content-Type: application/json
Authorization: 'Bearer ' + token

{
    "text": "hello",
    "as_user": true,
    "channel": "U##########"
}

• https://api.slack.com/methods/chat.postMessage
• https://stackoverflow.com/questions/47753834/how-to-send-direct-messages-to-a-user-as-app-in-app-channel
• https://stackoverflow.com/questions/50659252/json-post-request-to-slack-returns-invalid-auth/72239819#72239819

chat.postMessage API method

How to send direct messages to a user as app in app channel

JSON post request to slack returns invalid_auth