How do I upload contacts to iCloud before switching out iPhones?
How do I upload contacts to iCloud before switching out iPhones?
iPhone X, iOS 16
To sync contacts with iCloud, see the following article from Apple Support: Set up iCloud for Contacts on all your devices - Apple Support
If you want to verify that they are synced, use any Internet browser and log into www.icloud.com and check the Contacts app there.