You can define dynamic parameters inside a Stored Function in CustomJS using the panel at the right side of the screen.
All dynamic parameters you create here are accessible via input.PARAMETER_NAME.
In Make, they will automatically appear once you load the function using the Execute a Stored Function module.


You can then use these parameters in your JavaScript code by referencing them through the input variable.

You can retrieve JSON data directly from the Input field in a CustomJS Function but you have to parse it with JSON.parse().

In Make, you need to build a proper JSON object as a string, or construct it using Make modules. to convert Make collections into a JSON object, you must use the Transform to JSON module. To learn more, see Using JSON for Complex Data