code: public function run()
      {
          $this->registerClientScript();
          $input = $this->renderInputHtml('text');
          $route = $this->captchaAction;
          if (is_array($route)) {
              $route['v'] = uniqid('', true);
          } else {
              $route = [$route, 'v' => uniqid('', true)];
          }
          $image = Html::img($route, $this->imageOptions);
          echo strtr($this->template, [
              '{input}' => $input,
              '{image}' => $image,
          ]);
      }
docs: Renders the widget.