code: def render(self, template_name: str, **ctx):
          
          if '.' not in template_name:
              template_file_extension = (self.Meta.template_file_extension
                                         or app.config.TEMPLATE_FILE_EXTENSION)
              template_name = f'{template_name}{template_file_extension}'
          if self.Meta.template_folder_name and os.sep not in template_name:
              template_name = os.path.join(self.Meta.template_folder_name,
                                           template_name)
          return render_template(template_name, **ctx)
docs: Convenience method for rendering a template.
  
          :param template_name: The template's name. Can either be a full path,
                                or a filename in the controller's template folder.
          :param ctx: Context variables to pass into the template.