Yes, your child will own the account and thereby they can make use of a tax exemption order (Freistellungsauftrag). This can be activated directly in the Scalable App.
This can be filed in the Scalable App under Profile > Tax Exemption Order and on the Web under Profile > Taxes > Tax Exemption Order. Then select the account you wish to manage.
This only applies to Kids’ accounts in Germany. Scalable Capital does not provide tax advice. Tax treatment is individual and can change.