Can't get into Realms on Minecraft: Java Edition? Due to GDPR (http://minecraft.net/privacy/gdpr/ ) users under the age of 16 need parental consent to play on Realms. To set up parental consent on an account, visit http://minecraft.net/update-account .
Login issues with the website/launcher can be related to past interaction with third-party launchers/websites. While we can't provide insight to these kinds of issues, you may find helpful support at the community run help page: https://minecraftirc.net/minecrafthelp/landing/ … ^SA