email Button Merchant Library Version 1.6.1 Package Reference ButtonMerchantLibrary Namespace com.usebutton.merchant Classes ActivityReportingTask ButtonMerchant AttributionTokenListener ButtonProduct ButtonProductCompatible Order OrderListener PostInstallIntentListener UserActivityListener Exceptions ApplicationIdNotFoundException ButtonNetworkException HttpStatusException NetworkNotFoundException Modules com.usebutton.merchant.module ButtonUserActivity Features Email Property @ Nullable @get: Nullable open val email: String