About iCloud backups

It is possible to back up iOS devices not only locally, but also to iCloud. For more information, please read:

Creating an iCloud account: Frequently Asked Questions

iCloud: iCloud storage and backup overview

Manage your iCloud storage

Once you have enabled iCloud backup on your device (Settings | iCloud | Backup | iCloud Backup), it will run on a daily basis as long as the device is connected to Internet over Wi-Fi, connected to a power source, and has the screen locked.

If you have the Apple ID and password, you can access WhatsApp data in iCloud backups via EXWA. To download the whole iCloud backup, please use Elcomsoft Phone Breaker.