The documentation states: "Name identifier of the data, specified as a character vector or string scalar. This identifier is the same name identifier passed to setappdata during the storage operation."
But you seem to be confusing this function with accessing a property in AppDesigner. This function was introduced 2 decades before AppDesigner was released. I doubt you need it here.
What do you want to do? You really need to start improving your questions. Formatting and a longer explanation of the context of what you have and what you want help a lot. It can even help you answer your question before you post it.
