code: public void restoreSettings() {
          mCallbacks.printOutput("Restoring settings...");
          
          String settingUrl = mCallbacks.loadExtensionSetting(scan.getSettingsNamespace() + SETTING_URL);
          mCallbacks.printOutput("Match rules URL from settings: " + settingUrl);
          if (settingUrl != null) {
              urlTextField.setText(settingUrl);
              //extender.setFormUrl(settingUrl);
          }
      }
docs: Restores any found saved settings