There is a multiplatform application on Unity, as well as a website and applications on platforms that are not supported by Unity, in which there is a subscription (month, year ...) If a customer subscribes to one platform, the subscription must be valid for everyone. How on the server side to check whether the client’s subscription is valid for the application on Google Play (if the client has logged in, for example, on iOS or Smart TV)? Is it enough to know the client's email address? If not, what data is needed?