Specifies that an asynchronous version of the function should also be created.
If this property is set to true, then an additional add-in function will be created which runs the core function asynchronously, in a worker thread. The function will be have the same name as the core function, plus the suffix "Async".
The default value for the property is false.
An application-level asynchronous function controller must exist in order for this feature to work. Create an asynchronous function controller when creating the add-in project using the AppWizard.
Function Model | Function Properties | Asynchronous functions