Visual studio adding ASP.NET web reference error

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C#

IIS

Visual-Studio

webservice

When I'm adding a reference to my webservice in visual studio it throws that error:

Fehler beim Herunterladen von "https://xxxxxxxx/Test/WebService.asmx/$metadata".
Anforderung nicht erfolgreich mit HTTP-Status 403: Forbidden.

The service is configured to use https in IIS.
Opening the url in the browser is no problem.

I only get the error when I try to add it as a reference in visual studio.

I've read many articles how to solve that problem but no solution worked for me.

I'm running out of ideas please help me.

Greetings

What I have tried:

Made changes to the web.config but no solution.