test.cs

public IActionResult Index() {

   ViewModel model = new ViewModel();

   using (TXTextControl.ServerTextControl tx = new TXTextControl.ServerTextControl()) {
      tx.Create();
      tx.Load("App_Data/lease_agreement.tx", TXTextControl.StreamType.InternalUnicodeFormat);

      string svgSources = tx.GetPages()[1].GetImage(TXTextControl.Page.PageContent.All, 300);
      model.svgImage = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(svgSources));
   }

   return View(model);
}