How to fix app tracking issues on refurbished iPhone SE?

we just got a refurbished iPhone SE (2022 version) and we are unable to toggle app tracking to on. It says it’s because my “apple account is missing age information.”

I have updated, changed my birthday online AND on my phone. Started a brand new fresh Apple ID. Updated everything, signed out, signed in. Turned phone off turned back on.

I do not know what else to do! The whole reason we bought this phone was to use it specifically for money making game websites that require tracking. *sigh* please help!

[Re-Titled by Moderator]

Original Title: cant use app tracking due to