You verified your age, but Apple says "by birth year". It could be if one goes by year alone, you are still 17. Or at least that's my reading of it.
If an app asks to track your activity - Apple Support
"In some circumstances, the ‘Allow Apps to Request to Track’ setting can't be turned on, including:
For users with child accounts or who are under age 18 by birth year, signed in with their Apple Account*
Apple also says you can't turn it on:
If your Apple Account is managed by an educational or business institution
If your device is managed and uses a configuration profile that limits tracking
If your Apple Account was created in the last 3 days"
In addition, if an app or feature on your device is not working, not appearing, or is restricted (grayed out), a frequent reason is it may have been disabled using Screen Time, or by an IT administrator if you are using a device owned by an employer or educational institution.
- Read this support article If your Apple ID or other options are greyed out in Settings —> If your Apple Account is grayed out in Settings - Apple Support
Tap Settings > Screen Time > Content & Privacy > scroll to Allow Changes and turn on.
- If the device is managed (Settings > General > VPN & Device Management), contact the IT department that is doing the managing.
