How to call ip address using SSRS

You haven't actually explained what the problem is - "not work" is useless as a problem description.

At a guess, you were expecting the value of the valuereports variable to be magically inserted into the string passed to the Uri constructor. But C# doesn't work like that.

(Imagine the confusion if it did: if you declared a variable string name = "Bob";, and then tried to display a message of "Please enter your name:", you would actually display: "Please enter your Bob:"!)

Instead, you need to tell the compiler that you want to insert the value of a variable into the string. There are several ways to do that; the simplest is probably to use string interpolation[^]:

WithoutAddOns.ServerReport.ReportServerUrl = new Uri($"http://{valureports}:80/WebServiceURL");