Are you asking about updating the application, or the webmap?
If you are talking about the webmap, are you sending the webmap id as a query parameter or is it hardcoded in your app? If it's hard coded then you need to make sure you are editing the correct webmap with the id specified in your code, and you need to ensure that the people you want to update the webmap has the appropriate perms to do so.
if you are using query parameters then just make people have rights to edit the layers within the webmap
If you want them to update the web application, what about the web app do you want them to update?