title: What is the Tuya API referring to when they ask for the "schema" in some of their Open API calls?
body: <p>I have accessed the Tuya cloud using their API.  I can't use any of the API calls that uses the "schema".  I assume this is the name of my iOS app?  Does anyone have an example of a working call that uses "schema"?</p>
  
  <p>For example I have tried "sensorstat" and "com.status.sensor" while calling API "get user list".  I expected the API to give me a list of users registered through the application.</p>
  
  <p>I get a permission denied response.:
  {
      "code": 1106,
      "msg": "permission deny",
      "success": false,
      "t": 1559669799846
  }</p>