How to detect if dompdf page is changed?

Question

As per documentation, we print the page number on each pdf page but my problem is I want to use the PHP variables inside dom script tag which I can't do that.

<script type="text/php">
    if (isset($pdf)) {
      $font = $fontMetrics->getFont("Arial", "bold");
      $pdf->page_text(555, 745, "{PAGE_NUM}", $font, 7, array(0, 0, 0));
    }
</script>

@php
   $page = "{PAGE_NUM}";// it prints the string "{PAGE_NUM}" but I want current page number here
@endphp

My problem is that I want to use this {PAGE_NUM} inside my normal @php laravel blade file tag so that I can be able to detect the page change. Is there any way to do this stuff?.