Hi @leo del ciello ,
The way you configured it is incorrect. Do you want to authenticate by username and password?
You can take a closer look at the comments in the documentation.

The following documentation contains examples of how to create a service endpoint that uses a Windows domain username and password to protect the transport, which you can refer to.
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/transport-security-with-basic-authentication
How to: Authenticate with a User Name and Password
The documentation says that after selecting the security mode, you have to specify the actual credentials.
Set Windows Credentials: If the client specifies a valid username and password, it is used to authenticate the client. Otherwise, the currently logged in user's credentials will be used.
If you want to understand the difference between Transport Security's basic credential types and windows credential types, you can check out the following documentation.
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/transport-security-overview
Best regards,
Lan Huang
If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.