At the exit of the child is enough just a notarized consent of the parents. Apostille is not needed.

Apostille is not needed. Sufficiently ordinary notary certification with signature and seal.

To leave the child you need: notarized consent for the departure of the child (to the Schengen countries) in the ORIGINAL + copy + certified notarially German translation (if only one of two is traveling - from another if there is not one or both of them coming). The validity of the consent is no more than 6 months.