Generate report through the Web API for C #

I am starting the report part of my system, when making a request to generate a report on a new tab I can even do it by link passing a few parameters.

window.open(this.httpUtil.url('SinistroReports/' + search.DateStart +'/' + search.DateEnd +'/'), "_blank")

But I needed for all a POST serialized object, which until I know, I can not get through the window.open.

So I'm passing the attributes of my report to my API / POST and I generate my report, but I needed my API to open a new tab to view the report.

Does anyone have any tips / suggestions on how to proceed?