Sorry we do not have any information for your vehicle so there are no diagrams to show you. Engine oil is topped up from the oil filler cap on top of engine valve cover. You need to lift up the seats to get at it.
Check under the front hood to see if there is any container at left side of compartment if you are looking into it.
It would say engine oil with level. Some Toyota Tarago models do come with a reserve tank for engine oil.