Configuration.cs

public static class Configuration
{
    public static IEnumerable<ApiResource> ApiResources = new List<ApiResource>
    {
        new ApiResource("auth.web.api")
    };

    public static IEnumerable<Client> Clients = new List<Client>
    {
        new Client
        {
            ClientId = "ApiClient",
            AllowedGrantTypes = GrantTypes.ClientCredentials,
            ClientSecrets = new [] { new Secret("apisecret".ToSha256()) },
            AllowedScopes = new [] { "auth.web.api" }
        }
    };
}