How do I remove age restrictions on Xbox One?

Yes, I figured it out. For whatever reason, there was an age restriction on my Xbox account, probably for my little brother. Anyway, removing the age restriction and trying again worked for me. Try checking if you have any restrictions at all on
your account (Xbox or Microsoft) and remove them. This should work for you too.

How exactly did you remove the age restriction? I don´t know how to do that. My brother actually plays on the xbox and I would like to play some destiny 2 there. I play on PS4 and i am getting the same error. Do I change it on the xbox itself?

Yes, I figured it out. For whatever reason, there was an age restriction on my Xbox account, probably for my little brother. Anyway, removing the age restriction and trying again worked for me. Try checking if you have any restrictions at all on your account
(Xbox or Microsoft) and remove them. This should work for you too.

As far as I know you can not remove age restrictions until the birthdate attached to the account is of age.

So if you've changed your privacy and online settings to allow all content then I believe it would be as BIG has said and you will need to wait until the age on your account is at the required age to view the content.

This will most likely involved promoting to account from a child to an adult, if you're account is already an adult one, I'd be making a post here:

forums.xbox.com/.../4268.aspx

Medium bloke how do I change the age restrictions?