Unity IAP + Google Play Promo Codes

Hello there.

The second day I try to integrate into my Android game a system of promotional codes from Google (in my case - for making "consumable purchases"). The Unity IAP plug-in is installed and works, as well as the "playgameservices" plug-in. Codes received, but after activation and transition to the application there is no reaction. Tried to run the script of purchases right after the game start - the same.

The only more or less complete answer found here: https://github.com/playgameservices/play-games-plugin-for-unity/issues/1090 But this also did not help.

Here is my initialization code for purchases:

 public void InitializePurchasing()
     {
         if (IsInitialized())
             return;
         
         var builder = ConfigurationBuilder.Instance(StandardPurchasingModule.Instance());
         foreach (string s in C_PRODUCTS) builder.AddProduct(s, ProductType.Consumable);
         foreach (string s in NC_PRODUCTS) builder.AddProduct(s, ProductType.NonConsumable);
         UnityPurchasing.Initialize(this, builder);
     }

And the event of purchase:

 public PurchaseProcessingResult ProcessPurchase(PurchaseEventArgs args)
     {
         if (C_PRODUCTS.Length > 0)
             foreach (string c in C_PRODUCTS)
                 if (String.Equals(args.purchasedProduct.definition.id, c, StringComparison.Ordinal)) //C_PRODUCTS[currentProductIndex]
                     OnSuccessC(args);
 
         if (NC_PRODUCTS.Length > 0)
             foreach (string c in NC_PRODUCTS)
                 if (String.Equals(args.purchasedProduct.definition.id, c, StringComparison.Ordinal))
                     OnSuccessNC(args);
 
         return PurchaseProcessingResult.Complete;
     }

Who ever experienced this? What am I doing wrong?

PS: I'm sorry if I'm talking intricately or with mistakes. Rarely I write in English, but I have here also already 3 o'clock in the morning.