code: public function getDcaAttributes(PickerConfig $config): array
      {
          $attributes = ['fieldType' => 'radio'];
  
          if ($source = $config->getExtra('source')) {
              $attributes['preserveRecord'] = $source;
          }
  
          if ($this->supportsValue($config)) {
              $attributes['value'] = str_replace(['{{event_url::', '}}'], '', $config->getValue());
          }
  
          return $attributes;
      }
docs: {@inheritdoc}