You should have three oil lines going to the primary , a 1/4" supply , a 3/8" vent , and near the rear a 3/8" return . If these have not been blocked off then it is stock , and is a drip feed from the engine oil . You say there are three , so my guess is they haven't been blocked off ..
Look at the rear of the primary and you will find the drain plug ..
The trans is separate ..
The enclosed chain is the greatest invention of Harley history , There is a plastic cap on top of the cover for filling and one down low on the side for checking the level , remove the one for checking the oil level and if oil doesn't drain out , add until it does , use whatever grade motor oil you are using , only takes around six ounces .. It wont 'use' much , maybe a dollop every oil change , ya really don't have to change it , only add to it , which is rare , unless the seals are leaking .. Only issue is when you change rear tires , if you over torque the rear axle , the seals will leak ..
I envy you
JtB