I have a project where I am using NPOI to generate Excel document from my Angular application. I have the calls being made from my angular service to my webapi controller as fol
I had a similar problem. I solved that changing the endpoint to support GET and calling this method from a new tab.
So from your angular app you have to create a new tab pointing to the path that calls the method that generate your document. You can open a tab with the next code:
$window.open(path)
I think that in the next link you can have all the information that you need:
Download file from an ASP.NET Web API method using AngularJS
I hope that it helps.