// Create RateManager
var rateManager = new RateManager();

// Add desired shipping providers
// You will need a license #, userid and password to utilize the UPS provider.
rateManager.AddProvider(new UPSProvider(upsLicenseNumber, upsUserId, upsPassword));
// You will need an account # and meter # to utilize the FedEx provider.
rateManager.AddProvider(new FedExProvider(fedexKey, fedexPassword, fedexAccountNumber, fedexMeterNumber));
// You will need a userId to use the USPS provider. Your account will also need access to the production servers.
rateManager.AddProvider(new USPSProvider(uspsUserId));
// You will need a Site ID and Password to use DHL provider.
rateManager.AddProvider(new DHLProvider(dhlSiteId, dhlPassword, useProduction: false));

// (Optional) Add RateAdjusters
rateManager.AddRateAdjuster(new PercentageRateAdjuster(.9M));

// Setup package and destination/origin addresses
var packages = new List<Package>();
packages.Add(new Package(12, 12, 12, 35, 150));
packages.Add(new Package(4, 4, 6, 15, 250));

var origin = new Address("", "", "06405", "US");
var destination = new Address("", "", "20852", "US"); // US Address

// Call GetRates()
Shipment shipment = await rateManager.GetRatesAsync(origin, destination, packages);

// Iterate through the rates returned
foreach (Rate rate in shipment.Rates)
{
    Console.WriteLine(rate);
}

rateManager.AddProvider(new USPSProvider(uspsUserId, "Priority Mail"));
rateManager.AddProvider(new UPSProvider(upsLicenseNumber, upsUserId, upsPassword, "UPS Ground"));

var shipment = await rateManager.GetRatesAsync(origin, destination, packages,
    new ShipmentOptions() {
        SaturdayDelivery = true,
        ShippingDate = new DateTime(2020, 7, 15),
        PreferredCurrencyCode = "EUR",  // For FedEx only
        FedExOneRate = true             // For FedEx only
    });

var anySaturdayDeliveryMethods = shipment.Rates.Any(r => r.Options.SaturdayDelivery);

var shipment = rateManager.GetRates(origin, destination, packages);

foreach (var error in shipment.Errors)
{
    Console.WriteLine(error.Number);
    Console.WriteLine(error.Source);
    Console.WriteLine(error.Description);
}

foreach (var error in shipment.InternalErrors)
{
    Console.WriteLine(error);
}