Step 1:
i) Connect your device to a Wi-Fi network.
Step 2:
ii) In iOS 8 or later, tap Settings > iCloud > Backup. Make sure that iCloud Backup is turned on.
Step 3:
iii) Tap Back Up Now. Stay connected to your Wi-Fi network until the process completes.
Step 4:
iv) Make sure the backup finished by tapping
Settings > iCloud > Storage > Manage Storage, and then select your device.
NOTE:
The backup you just made should appear in the details with the time and backup size.