If you didn't turn on Screen Time while setting up your device, you can turn it on in Settings.
Open the Settings app, then tap Screen Time.
Tap App & Website Activity, then tap Turn On App & Website Activity.
Open the Settings app, then tap Screen Time.
Under Family, tap your child's name.
Follow the onscreen instructions to set age-appropriate Content & Privacy Restrictions, get a weekly Screen Time report, turn on other Screen Time settings, and lock the Screen Time settings and parental controls.
When you set up Screen Time on your child’s device, you can set age-related restrictions for content, purchases and downloads, and privacy settings. If you decide you want to set this up later, you can turn on Content & Privacy Restrictions in Screen Time.
Open the Settings app, then tap Screen Time.
Under Family, choose your child’s name.
Tap Content & Privacy Restrictions. If asked, enter your Screen Time passcode, then turn on Content & Privacy Restrictions.
If you turn off Content & Privacy Restrictions, any parental controls that you turned on will be paused until you turn on Content & Privacy Restrictions again.
Required and Recommended Settings for your child's iPad