How to implement a refresh button ?

[tudoroancea]

Hello there,
This is more of a question than a problem with your work.
I am new to Flutter development and to Provider. I would like to implement a refresh button in the app bar to fetch new data form the API. However I am not sure how to do that because the refresh method should be made asynchronous and I am not sure how to insert that in a Provider.
Any ideas or clues you can give me ? Thank you !