In a web app builder gis ,how do i add a button that call a web service that can be reached by a url and then when finish refresh the map?
If you have examples it will be nice.
You would develop a custom widget and call the web service using esriRequest.
Here is a JS API sample that uses esriRequest:
If you want the web service to be called from a button and not open a widget panel then you can look at my code for URL button widget on how to execute code on widget button click without have a panel open.