Blog page pagination links?

Site URL: http://fredfilms.com/shows

I have this script on my blog page:

<script>
  document.querySelectorAll('.BlogList-pagination-link-label').forEach(function(paginationLink) {
      if (paginationLink.textContent == "Newer") {
          paginationLink.textContent = "Previous page"; // Customize "Newer" text here
      } else {
          paginationLink.textContent = "Next page"; // Customize "Older" text here
      }
  })
</script>

It has successfully replaced the pagination link titles when I view the site through the squarespace editor, but now that the site is live and I'm viewing it on other browsers and not logged in to the admin it is still showing as Older/Newer

Any ideas how I can fix this so it works on the live site?