Fix checkout page

BTCPayServer/Controllers/InvoiceController.UI.cs

@@ -112,6 +112,7 @@ namespace BTCPayServer.Controllers
 
 			var model = new PaymentModel()
 			{
+				ServerUrl = HttpContext.Request.GetAbsoluteRoot(),
 				OrderId = invoice.OrderId,
 				InvoiceId = invoice.Id,
 				BTCAddress = invoice.DepositAddress.ToString(),

BTCPayServer/Models/InvoicingModels/PaymentModel.cs

@@ -11,7 +11,10 @@ namespace BTCPayServer.Models.InvoicingModels
 		{
 			get; set;
 		}
-
+		public string ServerUrl
+		{
+			get; set;
+		}
 		public string OrderId
 		{
 			get; set;

BTCPayServer/Views/Invoice/Checkout.cshtml

@@ -27,6 +27,7 @@
 			crossorigin="anonymous"></script>
 	<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.qrcode/1.0/jquery.qrcode.min.js"></script>
 	<script type="text/javascript">
+		var serverUrl = "@Model.ServerUrl";
 		var invoiceId = "@Model.InvoiceId";
 		var btcAddress = "@Model.BTCAddress";
 		var btcDue = "@Model.BTCDue"; //must be a string

BTCPayServer/wwwroot/js/core.js

@@ -69,7 +69,7 @@ function emailForm() {
             // Push the email to a server, once the reception is confirmed move on
             customerEmail = emailAddress;
 
-            var path = "i/" + invoiceId + "/UpdateCustomer";
+            var path = serverUrl + "/i/" + invoiceId + "/UpdateCustomer";
 
             $.ajax({
                 url: path,
@@ -192,7 +192,7 @@ function updateState(status) {
 }
 
 var watcher = setInterval(function () {
-    var path = "i/" + invoiceId + "/status";
+    var path = serverUrl + "/i/" + invoiceId + "/status";
     $.ajax({
         url: path,
         type: "GET"