title: How to request OAuth2 token to kong plugin
body: <p>i am following this tutorial <a href="https://medium.com/@far3ns/kong-oauth-2-0-plugin-38faf938a468" rel="nofollow noreferrer">https://medium.com/@far3ns/kong-oauth-2-0-plugin-38faf938a468</a> and when i request the tokens with</p>
  
  <pre><code>Headers: Content-Type:application/json
  Host:api.ct.id
  Body:
  {
  “client_id”: “CLIENT_ID_11”,
  “client_secret”: “CLIENT_SECRET_11”,
  “grant_type”: “password”,
  “provision_key”: “kl3bUfe32WBcppmYFr1aZtXxzrBTL18l”,
  “authenticated_userid”: “oneone@gmail.com”,
  “scope”: “read”
  } 
  </code></pre>
  
  <p>it returns </p>
  
  <pre><code>{
    "error_description": "Invalid client authentication",
    "error": "invalid_client"
  }
  </code></pre>
  
  <p>no matter what i tried i couldn't fix it, any idea how to make it work properly </p>