how do i change my microsoft account from child to adult

After 3 hours of chatting with Microsoft support, they had no solution other than the one on the web page, which is to contact the previous IT person we can't reach. Since the Microsoft account has an apparent age of 10 years old, these can't be turned off in Settings. This causes some apps to require parental permission, so Chrome won't work, even though Edge still does. Recently, the Parental Controls on the new computer were turned on because of the Microsoft account's apparent age, perhaps during a Windows Update. This makes the local Windows account attached to this Microsoft account have Administrator rights. On his new computer, I used his Microsoft account to log in to Windows the first time. She set the birthdate of the account to when she created it, added it to a Family group with herself as the 'parent.' We have no way of reaching her, and we don't want to make a new account and email address. This account was used to purchase software from Microsoft and other companies. Ten years ago, a private IT contractor set up my friend's Microsoft Account and email address when she set up his last computer. The birthdate on my friend's Microsoft Account is incorrect, and this is causing problems with some software such as Google Chrome.

How do i change my microsoft account from child to adult