payment-all.html

<div class="wrapper-body">
  <div class="container">

    <!-- Hidden error message block -->
    <div id="error" style="display:none">
        <p>There was an error processing your payment, please try again.</p>
    </div>

    <h2>Make a payment</h2>
    <p>Please make a payment of $100 AUD</p>
    <div>
      <!-- Embedded  eWAY Pay Now button -->
      <script src="https://secure.ewaypayments.com/scripts/eCrypt.js"
          class="eway-paynow-button"
          data-publicapikey="<your payment gateway API key goes here>"
          data-amount="10000"
          data-resulturl="https://payments-demo.powerappsportals.com/processing"
          data-currency="AUD" >
      </script>
    </div>

  </div>
  <div class="push"></div>
</div>

<script>

var urlParams = new URLSearchParams(window.location.search);
var error = urlParams.get('error');

// If there was an error - display a message
if(error)
  $("#error").show();  

</script>