Sign in with your Apple ID - Apple Support
support.apple.com › en-us › HT204053Jul 06, 2021 · Open the Settings app. Tap Sign in to your [device]. Enter your Apple ID and password. If prompted, enter the six-digit verification code sent to your trusted device or phone number and complete sign in. If you're already signed in to iCloud on the iPhone paired with your Apple Watch, you will automatically be signed in to that Apple ID.