How in Laravel run JavaScript code stored in php variable?

php laravel laravel-livewire

PHP Snippet 1:

public $foo;

$this->dispatchBrowserEvent('custom-event', ['foo' => $this->foo]);

PHP Snippet 2:

<script>
    window.addEventListener('custom-event', event => {
          alert('here value foo: ' + event.detail.foo);
          console.log(event.detail.foo);
    })
</script>

PHP Snippet 3:

<script>
    document.addEventListener('custom-event', () => {
        {!! json_encode($script) !!}
    })
</script>