Not 100% sure. But many vehicles with no trans dipstick, are filled from the drain plug. Usually there is a stand pipe above the drain hole, that keeps the fluid in the pan. Must be checked while running, so fluid does not run out. Basically, you start it, pull the drain and see if fluid comes out. If not you introduce fluid util it overflows the standpipe in the pan. Does that make sense ? Not sure if this is your application, but likely, if no dipstick
