Getting 401 Unauthorized on WhatsApp Cloud API via Mekari Qontak

need help from anyone familiar with whatsapp cloud api. I'm using the Mekari Qontak API https://github.com/mekari-engineering/qontak-api-js and follow the documentation provided in the repo.

Somehow my request here got response 401

curl --request POST \
  --url https://api.mekari.com/qontak/chat/v1/broadcasts/whatsapp/direct \
  --header 'Accept: application/json' \
  --header 'Authorization: hmac username=“{{Username}}“, algorithm="hmac-sha256", headers="date request-line", signature="{{Signature}}"' \
  --header 'Content-Type: application/json' \
  --data '{
  "to_name": "Test User",
  "to_number": "6281234567890",
  "message_template_id": "60cccaa0-ccd9-4efd-bdfb-875859c4b50a",
  "channel_integration_id": "56b60c3c-0123-46af-958b-32f3ad12ee37",
  "language": {
    "code": "id"
  },
  "parameters": {
    "buttons": [
      {
        "index": "0",
        "type": "url",
        "value": "123456"
      }
    ],
    "body": [
      {
        "key": "1",
        "value_text": "123454321",
        "value": "otp"
      }
    ]
  }
}'

Does anyone know what might cause this 401 error?

Are there specific steps needed for authentication, such as generating an HMAC signature?

Has anyone successfully sent messages using this API and can share a working example?

API key and credentials are correct.
The request headers match the API documentation.
The username, algorithm, headers, and signature are properly set in the Authorization header.
The message_template_id and channel_integration_id are valid.

Solution

Helo based on the docs here https://developers.mekari.com/docs/kb/hmac-authentication/node#creating-hmac-signature

you may need to add header 'Date' also with Format must follow RFC7231. Example: Wed, 10 Nov 2021 07:24:29 GMT

shouldbe like this

curl --request POST 'https://api.mekari.com/qontak/chat/v1/broadcasts/whatsapp/direct' \
        --header 'Authorization: hmac username="{{Username}}", algorithm="hmac-sha256", headers="date request-line", signature="{{Signature}}"' \
        --header 'Date: Fri, 28 Mar 2025 10:04:47 GMT' \
        --header 'Content-Type: application/json' \
        --data-raw '{
  "to_name": "Test User",
  "to_number": "6281234567890",
  "message_template_id": "60cccaa0-ccd9-4efd-bdfb-875859c4b50a",
  "channel_integration_id": "56b60c3c-0123-46af-958b-32f3ad12ee37",
  "language": {
    "code": "id"
  },
  "parameters": {
    "buttons": [
      {
        "index": "0",
        "type": "url",
        "value": "123456"
      }
    ],
    "body": [
      {
        "key": "1",
        "value_text": "123454321",
        "value": "otp"
      }
    ]
  }
}' | jq

voila!