Web API authorization issue via postman

 Web.Config:

    <add key="HmacAppId" value="c6afexxxxxxxxxxxxxxxxxxxxxxxxxxxx809" />
    <add key="HmacAPIKey" value="2ZajxxxxxxxxxxxxxxxxxxxxxxxxxxxFoO0=" />

 Request from Postman:

 Issue in CustomDelegetHandler.cs when after process request.Headers.Authorization, we found generated token but after   that it thrown UnAuthorized message in response in code and postman return response like uploaded image.