var tokenClient = new TokenClient("http://localhost:1000/connect/token", "client_id", "client_secret");

var scopes = "MyApi offline_access openid profile";

var tokenResponse = await tokenClient.RequestResourceOwnerPasswordAsync(request.UserName, request.Password, scopes);

var accessToken = tokenResponse.AccessToken;

var introspectionClient = new IntrospectionClient("http://localhost:1000/connect/introspect",
    "client_id", "client_secret");

var introspectResponse = await introspectionClient.SendAsync(new IntrospectionRequest()
{
    Token = accessToken
});