You can get the default proxy setting for a specific url with System.Net.WebRequest.GetSystemWebProxy().GetProxy().
The result is System.Uri object, and its OriginalString property will be the same the parameter if you are not behind a proxy:
PS C:\> [System.Net.WebRequest]::GetSystemWebProxy().GetProxy('https://login.microsoftonline.com/organizations/oauth2/v2.0/authorize') AbsolutePath : /organizations/oauth2/v2.0/authorize AbsoluteUri : https://login.microsoftonline.com/organizations/oauth2/v2.0/authorize LocalPath : /organizations/oauth2/v2.0/authorize Authority : login.microsoftonline.com HostNameType : Dns IsDefaultPort : True IsFile : False IsLoopback : False PathAndQuery : /organizations/oauth2/v2.0/authorize Segments : {/, organizations/, oauth2/, v2.0/...} IsUnc : False Host : login.microsoftonline.com Port : 443 Query : Fragment : Scheme : https OriginalString : https://login.microsoftonline.com/organizations/oauth2/v2.0/authorize DnsSafeHost : login.microsoftonline.com IdnHost : login.microsoftonline.com IsAbsoluteUri : True UserEscaped : False UserInfo :
The OriginalString property will be the same the proxy URL if if you are behind a proxy:
PS C:\> [System.Net.WebRequest]::GetSystemWebProxy().GetProxy('https://login.microsoftonline.com/organizations/oauth2/v2.0/authorize') AbsolutePath : / AbsoluteUri : http://140.227.25.56:5678/ LocalPath : / Authority : 140.227.25.56:5678 HostNameType : IPv4 IsDefaultPort : False IsFile : False IsLoopback : False PathAndQuery : / Segments : {/} IsUnc : False Host : 140.227.25.56 Port : 5678 Query : Fragment : Scheme : http OriginalString : http://140.227.25.56:5678 DnsSafeHost : 140.227.25.56 IdnHost : 140.227.25.56 IsAbsoluteUri : True UserEscaped : False UserInfo :
