Order complete redirect script for headless shopify

shopify-checkout-complete.html

<script>
  let base_url = 'https://zarashahjahan.com';
  let url = '';
  try {
    let order_id_sel = document.getElementsByClassName("os-order-number")
    let orderid = order_id_sel.length ? order_id_sel[0].innerText.toLocaleLowerCase().replace("order", "").trim() : null

    const mop =
      document.getElementsByClassName('payment-method-list_item_info')
        .length !== 0
        ? document.getElementsByClassName('payment-method-list_item_info')[0]
            .innerText
        : 'Cash on Delivery (COD)';
    if (mop === 'Cash on Delivery (COD)') {
      const obj = {
        order_id: orderid || Shopify.checkout.order_id,
        phone: Shopify.checkout.billing_address.phone
      };
      const stringifiedObj = btoa(JSON.stringify(obj));
      url = `${base_url}/order-verification?data=${stringifiedObj}`;
    } else {
      url = `${base_url}/thank-you?id=${Shopify.checkout.order_id}`;
    }
  } catch (err) {
    url = `${base_url}/thank-you`;
  }
  window.location.replace(url);
</script>