title: Facebook Messenger bot welcome message: 100 The parameter setting_type is required
body: <p>I'm trying to set a welcome message for a Facebook Messenger bot using the code provided in the documentation - with my own page ID and page access token</p>
  
  <pre><code>curl -X POST -H "Content-Type: application/json" -d '{
    "setting_type":"call_to_actions",
    "thread_state":"new_thread",
    "call_to_actions":[{
        "message":{
            "text":"Hello! This is a Messenger bot!"
        }
    }]
  }' "https://graph.facebook.com/v2.6/&lt;PAGE_ID&gt;/thread_settings?access_token=&lt;PAGE_ACCESS_TOKEN&gt;"
  </code></pre>
  
  <p>This returns the following:</p>
  
  <pre><code>{"error":{"message":"(#100) The parameter setting_type is required","type":"OAuthException","code":100,"fbtrace_id":"B0DKyn9O2KB"}}
  </code></pre>
  
  <p>Any ideas on how to solve this? Thanks.</p>