Use these steps from Apple Support to start a backup immediately:
Backing up your iPhone, iPad, or iPod touch to iCloud ensures your data is safe and easy to restore if you lose your device or get a new one. You can set up automatic daily backups or perform a manual backup at any time. back up to i cloud
Once enabled, iCloud will automatically back up your device daily when these conditions are met: Back up iPhone - Apple Support Use these steps from Apple Support to start
You can see the date and time of your last successful backup directly under this button. : Stay connected to Wi-Fi until the process completes
: Stay connected to Wi-Fi until the process completes.
: Ensure your device is connected to a Wi-Fi network.
: Tap your name at the top of the Settings app. Go to iCloud : Tap iCloud > iCloud Backup .