How to recover permanently deleted data in icloud

It's erased after 30 days permanently and can't be recovered if a single iPhone was used .

See the article How to back up your iPhone, iPad, and iPod touch with iCloud - Apple Support 

Automatically back up with iCloud Backup

Follow these steps to set up iCloud Backup to automatically back up your device each day:

1. Make sure that iCloud Backup is turned on in Settings > [your name] > iCloud > iCloud Backup.
2. Connect your device to a power source.
3. Connect your device to a Wi-Fi network.
4. Make sure that your device's screen is locked.
5. If you get an alert says that you don't have enough iCloud storage space to complete the backup, follow the onscreen steps to buy more storage.

Note : if automatically back up with iCloud backup was always turned as on the iCloud data were saved on iCloud , if not then it can't be recovered unless you backed up somewhere else in Mac / pc Backup methods for iPhone, iPad, and iPod touch - Apple Support

Then the data can be recovered .