How to upgrade a paid subscription?

Question

Android

I have been digging into the billing API for quite a long time and cannot figure out how to upgrade a paid subscription so that, for example, a monthly subscription is replaced by an annual one. If I use the getBuyIntent() method everything works great. But in the case of getBuyIntentToReplaceSkus() , an empty Bundle is returned (Bundle[EMPTY_PARCEL]).

List<String> oldSkus = new ArrayList<>();
oldSkus.add("some_monthly_subscription"); // Старая ежемесячная подписка

String sku = "some_yearly_subscription"; // Новая ежегодная подписка

Bundle buyIntentBundle = mService.getBuyIntentToReplaceSkus(
                    API_VERSION,
                    mContext.getPackageName(),
                    oldSkus,
                    sku,
                    "subs",
                    developerPayload);

buyIntentBundle.get("RESPONSE_CODE"); // null
buyIntentBundle.getParcelable("BUY_INTENT"); // null

Why? How to deal with it?