Family Sharing Function

Hello Iuan,

Unfortunately you cannot. Managing Family Sharing requires using an Apple device. Some Apple services are a available if you log into iCloud.com but Family Sharing isn't one of them. Additionally you can use some services on a PC or Android, but despite somewhat confusing phrasing such as "When you get an Apple Music family subscription, you can start and manage a family group to share your subscription" in the article Use Family Sharing with Apple Music on Android - Apple Support, apparently that is limited to sharing Apple Music and not full management you might wish to have available with a child.