To exchange data with an external app, click the "Add Another" button to add a parameter to your Method. Give the parameter a name - this is what will be sent to the API - and then map the parameter to an Attribute. In Figure 110 an API parameter has been created called "player_health" which is mapped to Audience.health.
Now, when the API issues a POST instruction, the value of the player_health parameter (e.g. " player_health=6") will be passed to an Audience member's health Attribute.
The same Method is used for POST (update the Attribute value) and GET (retrieve the Attribute value).
A GET instruction will return all parameters in the method. For method below a GET returns:
A POST instruction must include ALL parameters in the method or else parameters not included will set the Attributes to NULL