See -> If you forgot your Screen Time passcode
If you forgot your Screen Time passcode - Apple Support
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Then:
If it is a private iPhone, see -> Use parental controls on your child's iPhone, iPad and iPod touch
Use parental controls on your child's iPhone, iPad and iPod touch – Apple Support (UK)
- 👉 Check restrictions -> tap Settings -> Screen Time -> Content & Privacy -> scroll to Allow Changes.
or
If you have a MDM profile, you need to contact your company - IT department.
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If your Apple ID says it's inactive you need to reach out for support from Apple directly ->
Get Support