Firefox 138 - Script "F12 schließt Tab" geht nicht mehr

(function() {
 if (!window.gBrowser)
   return;
 for (let key of document.querySelectorAll('key[keycode="VK_F12"]')) {
   key.setAttribute('disabled', 'true');
 }
 let key = document.createXULElement('key');
 key.id = 'closeTab';
 key.setAttribute('keycode', 'VK_F12');
 // key.setAttribute('oncommand', 'gBrowser.removeTab(gBrowser.selectedTab, {animate: true})');
 document.getElementById('mainKeyset').appendChild(key);
 document.getElementById('closeTab').addEventListener('command', () => {
	gBrowser.removeTab(gBrowser.selectedTab, {animate: true})
 });
})();

(function() {
 if (!window.gBrowser)
   return;
 for (let key of document.querySelectorAll('key[keycode="VK_F12"]')) {
   key.setAttribute('disabled', 'true');
 }
 let key = document.createXULElement('key');
 key.id = 'closeTab';
 key.setAttribute('keycode', 'VK_F12');
 //key.setAttribute('oncommand', 'gBrowser.removeTab(gBrowser.selectedTab, {animate: true})');
 key.addEventListener('command', () => {
     gBrowser.removeTab(gBrowser.selectedTab, {animate: true});
   });
 document.getElementById('mainKeyset').appendChild(key);
})();