You have to be at least 13.
Quote
“While we appear “12+” on the Apple Store and “Teen” on the GooglePlay store, our platform is intended for teenagers 13+. In fact, players under the age of 13 are prohibited from using our service. If there is a case where you know about an underage player, please report them, and they will be removed from our platform.”
From: Content Guidelines
11 and 12 year olds or anyone under that age shouldn’t be on the Forums or writing stories as the Forums and stories are meant for 13+ up. If someone were to comment their age publicly, they’d be suspended if they’re underage.