In Pokémon HOME, your age status will be updated the month after your birth month.
This means that users who turn 16 after downloading the application will be able to use age-restricted features such as "Friend Trade" on the first day of the month after they turn 16.
If you cannot use such functions even the month after you turn 16, there is a possibility you input your birthday incorrectly on the first startup of the application.
Additionally, the age input at the first startup will take precedence, not the age that is set on the user's Nintendo Account.
Unfortunately, we are sad to inform users that there is no way to change the birthday settings after the first startup of the application.
Thank you for your kind understanding in this regard.