Execute SSRS Report from C# save as PDF

So, here's my delema.

The title says it all. I cannot seem to find any guidance on how to execute a SSRS report remotely and save it as a PDF.

I have tried to follow the below article. Using Reporting Services (SSRS) as a reference in an ASP.NET Core site

However, when I add the Service Reference to my project some of the methods seem to have the wrong signatures.

For example. rsExec.LoadReportAsync(report, null);

in my reference the first parameter is a TrustedUserHeader object.

Does anyone have a good starting point on how to execute an SSRS report from C#? I cannot find any simple example.