In the section "Purchase and subscription" there is an option "Payload" of the developer.
This developer option is used to store your purchase information, where you can store your unique purchase data. (For example, purchased registered email id for your application)
Thus, whenever another user logs in to your application, you can get purchase information with a developer payload. Thus, the obtained payload data of the developer corresponds to the login user, if so, then this is the same user login that was otherwise acquired by another user.
There is one drawback: another user login cannot purchase the same item if it purchased the same account.
This method is useful if you bought the one that you used to buy this item, but if any other user can also enter it on this device, but it should not use this item if it was not purchased for it.
This can also be controlled by the API.
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