How to show and edit the Java Scipt in a block

I have Java Script in a block in one of my web pages and need to eliminate/edit it but I see no way how to make it visible in nicepage editor. The code had been inserted long ago, probably as an HTML element. How can I edit this code? The block id is "sec-d5c9"

For some unknown reason, the script is now present 3 times in the block. I had inserted it only once.
This is what I see with Atom editor:

<section class="u-clearfix u-grey-10 u-section-6" id="sec-d5c9">
  <div class="u-clearfix u-sheet u-sheet-1">
    <div class="u-clearfix u-custom-html u-expanded-width u-custom-html-1"></div>


    <div class="u-clearfix u-custom-html u-expanded-width u-custom-html-2"><!--Start of Tawk.to Script-->
      <script type="text/javascript"> var Tawk_API=Tawk_API||{}, Tawk_LoadStart=new Date();
      (function(){
      var s1=document.createElement("script"),s0=document.getElementsByTagName("script")[0];
      s1.async=true;
      s1.src='https://embed.tawk.to/######################';
      s1.charset='UTF-8';
      s1.setAttribute('crossorigin','*');
      s0.parentNode.insertBefore(s1,s0);
      })(); </script><!--End of Tawk.to Script-->
    </div>


    <div class="u-clearfix u-custom-html u-expanded-width u-custom-html-3"><!--Start of Tawk.to Script-->
      <script type="text/javascript"> var Tawk_API=Tawk_API||{}, Tawk_LoadStart=new Date();
      (function(){
      var s1=document.createElement("script"),s0=document.getElementsByTagName("script")[0];
      s1.async=true;
      s1.src='https://embed.tawk.to/######################';
      s1.charset='UTF-8';
      s1.setAttribute('crossorigin','*');
      s0.parentNode.insertBefore(s1,s0);
      })(); </script><!--End of Tawk.to Script-->
    </div>


    <div class="u-clearfix u-custom-html u-expanded-width u-custom-html-4"><!--Start of Tawk.to Script-->
      <script type="text/javascript"> var Tawk_API=Tawk_API||{}, Tawk_LoadStart=new Date();
      (function(){
      var s1=document.createElement("script"),s0=document.getElementsByTagName("script")[0];
      s1.async=true;
      s1.src='https://embed.tawk.to/######################';
      s1.charset='UTF-8';
      s1.setAttribute('crossorigin','*');
      s0.parentNode.insertBefore(s1,s0);
      })(); </script><!--End of Tawk.to Script-->
    </div>
  </div>
</section>

Last edited 4 weeks ago by v.piasta