Children under age 12 do not have to provide their fingerprints but if they are between 6 and 12 years old, their photo has to be taken and they have to sign their passport. Therefore, as soon as children are six years old, they have to be present when their passport is applied for.
If it is impossible to take fingerprints because of a physical disability, alternative solutions are provided for. Your embassy or consulate will provide you with information in this regard. You will nonetheless have to be present in person when you apply for your passport in order to have your photo taken.