Properties
API
These were the list of APIS which you have created in the project dashboard. Whichever API you selected here will be called initially when the user enters that particular Screen. Know more
Text Properties
You can replace text content by added data from API's, User (if logged in), List Item and Params as simple as shown in the above images.
Image Properties
Same like text content you can also replace the image url with API's, User (if logged in), List Item and Params.