test.cs

// create the pre-populate data object
HealthcareForm data = new HealthcareForm() {
  insurance_date = DateTime.Now,
  insurance_name = "Global Health",
  insurance_check = true,
  insurance_state = "North Carolina",
  notes = "Thanks for your business."
};

using (TXTextControl.ServerTextControl tx = new TXTextControl.ServerTextControl()) {
  tx.Create();
  // load the template
  tx.Load("App_Data/health_form.tx", TXTextControl.StreamType.InternalUnicodeFormat);

  using (MailMerge mm = new MailMerge()) {
    mm.TextComponent = tx;
    
    // pre-populate the form fields
    mm.FormFieldMergeType = FormFieldMergeType.Preselect;
    mm.MergeObject(data);
  }

  // save document as PDF
  byte[] document;
  tx.Save(out document, TXTextControl.BinaryStreamType.AdobePDF);
}