Every screen has an specific structure, so you need to access Traken backend to get screen specification.
Just go to "Templates" and click on the screen you need to connect.
You have sample code under "Example" tab, both request and sample response.
The tab “response format” will bring you a lot of information about the widgets and the fields we need.
The response received should validate agains the JSON Schema shown under "JSON Schema" tab. You can use JSON Schema Validator to test it.
You have more information in our developers documentation.