[Help!] Fighting with Receipt Validation (iOS)

I've tried several ways to validate receipts and can't seem to get past it. My latest try is this:

 public void ValidateReceipt() {
 bool validPurchase = false;
 Product[] products = m_StoreController.products.all;
 
 try {
 CrossPlatformValidator validator = new CrossPlatformValidator (null, AppleTangle.Data (), Application.bundleIdentifier);
 for (int i = 0; i < products.Length; i++) {
 if (products .receipt != null) { // <--- This is always null
 IPurchaseReceipt[] result = validator.Validate (products .receipt);
 for (int j = 0; j < result.Length; j++) {
 if (result [j].productID == kProductIDNonConsumable) {
 Debug.Log(result [j].productID);
 validPurchase = true;
 }
 }
 } else {
 Debug.Log("Null Value " + products.transactionID);
 }
 }
 } catch (Exception ex) {
 Debug.Log(ex.ToString ());
 }
 
 if (validPurchase) {
 // SUCCESSFUL RECEIPT VALIDATION
 } else {
 // RECEIPT NOT VALID
 }
 }

The receipt is always null in this example. I've always played with... var builder = ConfigurationBuilder.Instance(StandardPurchasingModule.Instance()); string receipt = builder.Configure().appReceipt;

But again, the receipt is always null.

Has anyone gotten this working?