Interface was developed using VS2015. After running the back-end API in debug mode, Postman called the interface and sent back an error message:
< title> IIS 10.0 Detailed error-401.2-unauthorized< /title>
< h4> The most likely reason :& Lt; /h4>
& lt; ul>
& lt; li> No authentication protocol (including anonymity) was selected in IIS. < /li>
& lt; li> Only integrated authentication is enabled, and the client browser used does not support integrated authentication. < /li>
& lt; li> Integrated authentication is enabled, and the request is issued through a proxy, but the proxy changes the authentication header before the request reaches the Web server. < /li>
& lt; li> The Web server is not configured for anonymous access and does not receive the required authorization headers. < /li>
& lt; li>” The configuration/system. WebServer/authorization “configuration section may explicitly rejected the user access. < /li>
& lt; /ul>
Solution: Project – Properties – Anonymous Authentication – has been enabled