ClientCredentials.cs

 public async Task<IActionResult> CallApiUsingClientCredentials()
{
    var tokenClient = new TokenClient("http://localhost:5000/connect/token", "mvc", "secret");
    var tokenResponse = await tokenClient.RequestClientCredentialsAsync("Api1");

    var client = new HttpClient();
    client.SetBearerToken(tokenResponse.AccessToken);
    var content = await client.GetStringAsync("http://localhost:5001/api/resource-without-policy");

    return View("Json", content);
}