Open iCloud.com and log in to your account. Select All from the drop-down menu to mark all of your contacts for export.
Using the Contacts app, you may remove contacts on your iPhone one at a time. If you just want to erase one or more of your contacts, you’ll need to use iCloud. You may also delete your iPhone contact list if you want to sever ties permanently.
Go to Settings > [your name] and select iCloud. Select Manage Storage > Backups. Choose the device for which you want to delete a backup. Delete the backup by tapping Delete Backup > Turn Off & Remove