I discovered what happens: I need to load at least one url before loading the custom js functions. I loaded http://example.com before the custom js functions worked fine in "Run Mode".
So simple...
Thank you all
it's Working on Normal Browser With console command
document.body.innerHTML = '<iframe width="560" height="315" src="https://www.youtube.com/embed/GtZaKSWGJFE" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>';
or
document.getElementsByTagName('body')[0].innerHTML = '<iframe width="560" height="315" src="https://www.youtube.com/embed/GtZaKSWGJFE" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>';

But it's Not Working on BAS Via Browser Javascript command
