cosmos-trigger-fire-csharp.cs

var documentClient = new DocumentClient(new Uri("https://youraccount.documents.azure.com:443/"), "yourkey");

var collectionLink = UriFactory.CreateDocumentCollectionUri("Orders", "Orders");
var result = await documentClient.CreateDocumentAsync(collectionLink, documentToInsert, new RequestOptions
{
    PreTriggerInclude = new List<string> { "validateOrder" },
    PostTriggerInclude = new List<string> { "addRefund" }
});