Using App Properties in the Mapper
You can use app properties when mapping an input field. The app properties available for mapping are grouped under the $property domain-specific scope in the mapper. All mapper rules and conditions apply to the use of app properties as well. For example, the data type of the app property value must match with the input field data type when mapping. Connection-related app properties that are used by any connection field in an activity do not appear under $property since they cannot be accessed. Connection-related app properties cannot be used for configuration anywhere within an app. Their only purpose is to allow you to change a connection value if need be during runtime. Hence, they cannot be used to map input fields.
Refer to the section on Mapper for details on how to use the mapper.