Mtd Yard Machine Parts, Nh MTD Yard Machines Lawn Tractor, How Do I Add Oil To The Gear Box There Is No Filler Hole?

MTD Yard machines lawn tractor, how do I add oil to the gear box there is no filler hole? - mtd yard machine parts, nh

Model No. 13ai675h062

Serial 1b131b30253

I checked the manual and is the bill for filling in a hole, but none are listed in the figure or in parts