Please provide us more information. You said you aren't able to add the same service in ASP.NET 6.0. How are you adding it? Are you using a Connected Service? Are you using the svcutil tool to generate the proxy? Are you trying to reuse code written for .NET 4.x to talk to .NET 6? Providing any relevant code would help here.
Note that WCF service metadata is generally exposed as {svcurl}?wsdl
assuming you have enabled MEX and haven't changed the URL. Also note that you need to use either http
or https
depending on how the service is configured to return metadata.