Sync for the first time the CloudKit data

My app backup the data to iCloud or sync with user device through the user iCloud account using NSPersistentCloudKitContainer privateDataBase. The main problem is, when user install the app I need to know if user has data in iCloud or not according this information, I let user to setup account or fetch the existing account, since it takes too long to fetch with local CoreData, I am trying to find a way to fetch directly from iCloud through CloudKit, since I am new in CloudKit, I don't know how to fetch data from CloudKit any help appreciate.

Sync for the first time the CloudKit data
 
 
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