code: function isChromeExtensionAvailable(callback) {
          if (!callback) return;
  
          if (DetectRTC.browser.name === 'Firefox') return isFirefoxExtensionAvailable(callback);
  
          if (window.IsAndroidChrome) {
              chromeMediaSource = 'screen';
              callback(true);
              return;
          }
  
          if (chromeMediaSource == 'desktop') {
              callback(true);
              return;
          }
  
          // ask extension if it is available
          window.postMessage('are-you-there', '*');
  
          setTimeout(function() {
              if (chromeMediaSource == 'screen') {
                  callback(false);
              } else callback(true);
          }, 2000);
      }
docs: this method can be used to check if chrome extension is installed & enabled.