Authorization has been denied for this request - New Web API Project

Question

I just created new Web API project (using MVC) in visual studio 2015 and for the testing purpose, I ran that project but ended up below error.

After running the project,

Answer 1

It happens because you have an Authorize attribute on your ValuesController

[Authorize]
public class ValuesController : ApiController

Just remove [Authorize] and try again

EDIT

According to your edit: You should create a new user and login or use [AllowAnonymous] as mentioned by @Marcus H. Read more about Identity