First off, ionic-native is dead and was renamed to awesome-cordova-plugins.
Second, you are including two completely separate plugins.
@awesome-cordova-plugins/in-app-purchase-2 and cordova-plugin-purchase belong to Fovea.
@awesome-cordova-plugins/purchases and cordova-plugin-purchases belong to RevenueCat. The Awesome Cordova Plugin is outdated and has been deprecated by RevenueCat in lieu of their “new” Capacitor plugin that is currently in Beta since they took it over from CapGo.