Xcode: Where is the Entitlements.plist file?
You can add entitlement from Project Target.
you project Target -> Capabilities ->Background Mode-> ON-> select checkbox for Remote notifications
When we are using push notifications related code in our app and if that capability is not configured in Xcode or in App ID that mail comes from apple. If you are not going to use Push notifications in your app, then you can ignore that mail. But if you are using it, enable that capability in Xcode-> Target--> Capabilities --> Push Notifications
or
Go to developer portal and check enable push notifications capability for your App ID and enable it if it's disabled.