This has been driving me batty for over an hour. I'm new to EasyPost and I'm trying to put some custom text on my label (in my particular case, it is which SKU to put in the package), but it just never seemed to work. I'm using the official nuget package from easypost but am guessing it is platform independent.
Shipment shipment = new Shipment() {
to_address = toAddress,
from_address = fromAddress,
parcel = parcel
};
shipment.Create();
var lowestRate = shipment.LowestRate(includeServices: new List<string>() { "First" }, includeCarriers: new List<string>() { "USPS" });
shipment.Buy(lowestRate);
shipment.options.Add("print_custom_1", "this is some sample text");
shipment.options.Add("print_custom_2", "abc");
shipment.options.Add("print_custom_3", "xyz");
shipment.GenerateLabel("pdf");