Where can I add oil to an older forklift?

Tell a true joke, I have a friend's Longgong 850, Wei Chai engine, change the oil. He went to buy oil and called the driver to let him go. When he came back, guess what, there was not a drop of engine oil, and the hyperbolic oil was put clean before and after, and he plausibly pointed to the axle housing and said, isn't this an oil pan? Do you think such a driver can do it?