Button der in der url etwas ändert

(function() {

  if (window.__SSi != 'window0')
    return;

  CustomizableUI.createWidget({
    id: 'url-replace-button',
    defaultArea: CustomizableUI.AREA_NAVBAR,
    label: 'URL ersetzen',
    tooltiptext: 'URL ersetzen',
    onCommand: onCommand,
    onCreated: function(button) {
      button.style.listStyleImage = 'url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0iAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAgY0hSTQAAeiYAAICEAAD6AAAAgOgAAHUwAADqYAAAOpgAABdwnLpRPAAAAAlwSFlzAAAWJQAAFiUBSVIk8AAAAANQTFRFAP8ANF7AqAAAAAxJREFUCB1jYCANAAAAMAABhKzxegAAAABJRU5ErkJggg==)';
    }
  });

  function onCommand(event) {
    let frameScript = function() {
      let url = content.location.href;
      if (url.includes('.de/')) {
        content.location.href = url.replace('.de/', '.com/');
      };
    };
    let frameScriptURI = 'data:,(' + frameScript.toString() + ')()';
    let window = event.target.ownerGlobal;
    window.gBrowser.selectedBrowser.messageManager.loadFrameScript(frameScriptURI, true);
  };

})();