code: public function getFastlyUrl()
      {
          $baseFile = $this->getBaseFile();
          $url = $this->getBaseFileUrl($baseFile);
  
          $imageQuality = $this->_scopeConfig->getValue(Config::XML_FASTLY_IMAGE_OPTIMIZATION_IMAGE_QUALITY);
  
          $this->setQuality($imageQuality);
  
          $this->fastlyParameters['quality'] = $this->_quality;
  
          if ($this->_scopeConfig->isSetFlag(Config::XML_FASTLY_IMAGE_OPTIMIZATION_BG_COLOR) == true) {
              $this->fastlyParameters['bg-color'] = implode(',', $this->_backgroundColor);
          }
          if ($this->_keepAspectRatio == true) {
              $this->fastlyParameters['fit'] = 'bounds';
          }
          $this->fastlyUrl = $url . '?' . $this->compileFastlyParameters();
      }
docs: Creates a url with fastly parameters