How do I put my child’s gmail account in. It has name@icloud.com
How do I set up Apple ID for my child under 13 with their own gmail account and not an iCloud one
iPad Air 5 Wi-Fi
Note the restrictions in the article.
Make sure you turn off Find My Phone before signing out of the old ID. Once signed out and Find My Phone is off, then sign in with the new ID, then turn Find My Phone back on.
What to do after you change your Apple ID or password - Apple Support * I suggest doing this before you change your Apple ID or password.