Report server authentication

I am toying with connecting the PHP ReportViewer to render reports on an SSRS report server.  I am not having much luck getting my simple test report to render because I keep getting unauthorized or not found error messages.  I wonder how you provide authentication to the report server web service, did I miss this in the documentation?

<?php $reportviewer = new EJ\ReportViewer('territorysales_reportViewer'); echo $reportviewer->reportServiceUrl("http://js.syncfusion.com/ejservices/api/ReportViewer" )->processingMode("Remote")->reportServerUrl("http://mvc.syncfusion.com/reportserver")->reportPath("/SSRSSamples2/Territory Sales new")->render(); ?

<div class="cols-sample-area">          <?php          $reportviewer = new EJ\ReportViewer('groupingaggregate_reportViewer');                             echo $reportviewer->reportServiceUrl("http://localhost:62610/api/ReportApi" )->processingMode("Remote")->reportPath("GroupingAgg.rdl")->                               reportServerUrl("http://syncdeskn6533/ReportServer")->reportPath("/HyperLink")->render();          ?>      </div>

public void OnInitReportOptions(ReportViewerOptions reportOption)          {              //provide the SSRS server login credentials as shown in below line              reportOption.ReportModel.ReportServerCredential = new System.Net.NetworkCredential("ssrs", "RDLReport1");                //if datasource is shared datasource then please provide datasource credentials as shown in below line              reportOption.ReportModel.DataSourceCredentials.Add(new DataSourceCredentials("AdventureWorks", "ssrs1", "RDLReport1"));          }

Thank you for the response, this is helpful.  The piece that was not clear in your documentation was that the report server API had to be there.  I was thinking this reportviewer would be able to talk to the SSRS report server without having to have another API running but this makes sense now the way it is configured.  I guess the question I have now is if it is required that the report server API has to have connectivity to the SSRS report server, e.g. be on the same domain or have ability to connect to it?  What I'm getting at is let's say the report server API was on in the cloud and the report server was on a local intranet not accessible to the report server API, this will not work correct?  The report server API has to have connectivity to the SSRS report server correct?

What I'm getting at is let's say the report server API was on in the cloud and the report server was on a local intranet not accessible to the report server API, this will not work correct?  The report server API has to have connectivity to the SSRS report server correct?

Yes, your assumption is correct, We need service API to have connectivity with the SSRS report server to get the report.