use ConfigurationManager to call the value of a custom tag in app.config

I created a Rest web API and now I want to call the operations exposed by the API from a Proxy. My environment is Visual Studio, C#.

As the operations that I exposed in the API share a part of the URL/endpoint (“_api/NameOfTheController_“), I want to refer to this piece of URL by creating a custom tag in the _app.config_ file of the Proxy project; I’m gonna call it by using ConfigurationManager to initialize a property of the Proxy.

How should I use the ConfigurationManager class to call the value of the custom tag?

What I have tried:

In the app.config of the proxy I wrote thee following tag, inside the <client> tag:

`<customEndpointSegment name = “/api/NameOfTheController” />
`

Inside the same <client> tag there is a <endpoint> tag which points to another different service too.

In the Proxy.cs I have the following:

“`
string webApiEndpoint;
HttpClient client;

public RestProxy()
{
webApiEndpoint = ConfigurationManager. // I have to call the value of the tag here
client = new HttpClient();
client.BaseAddress = webApiEndpoint;
}
“`