How to modify Unsubscribe Page In Shopify?

{% if request.path == '/account/unsubscribe' %}
  {% capture new_content %}
    <style>
      .shopify-email-marketing-confirmation__container {
          padding-top: 4rem;
          text-align: center;
          padding-bottom: 4rem;
          visibility: visible!important;
      }
      main#MainContent {
          background: #000;
          color: #fff;
      }
    </style>
    <img height="100" src="https://www.masonsofyorkshire.com/cdn/shop/files/logo-white_x90_366bbf78-b54a-4b4c-9348-9befc609d44b_x100.png?v=1613725793" alt="Rain Designs Boutique Logo">
    <p>Sorry to see ya go!</p>   
  <p>You won’t receive any more marketing updates from us. You can subscribe again at any time.</p>
  {% endcapture %}
  <style>
    main#MainContent {
        background: #000;
        color: #fff;
    }
    .shopify-email-marketing-confirmation__container{
      visibility: hidden;
    }
  </style>
  <script>
    document.addEventListener('DOMContentLoaded', function() {
        document.querySelector('.shopify-email-marketing-confirmation__container').innerHTML = `{{ new_content }}`;
    });
  </script>
{% endif %}