Download Button Example not working

Hello, I followed step by step this example: to use the Radzen button to download a PDF file.
but it's not working. If I put a breakpoint I see that the method it's called correctly but then the "UriHelper.NavigateTo" return the error message "Sorry, but there's nothing here!". ( the controller is never called) , probably there is some routing error. could you please share the entire source code ?
( there is for angular but not for blazor ) I am a beginner and probably I am missing something....
maybe there is some other file to modify not mentioned in the example.
thank you in advance.
your product it's great.