func restoreProducts() {
     SKPaymentQueue.default().restoreCompletedTransactions()
    }

This method has no effect in the following situations:

• All transactions are unfinished.
• The user did not purchase anything that is restorable.
• You tried to restore items that are not restorable, such as a non-renewing subscription or a consumable product.
• Your app’s build version does not meet the guidelines for the CFBundleVersion key.