The word "apon" appears to have a typo or may not be a recognized English word. It is likely that you intended to use the word "upon." "Upon" is a preposition that indicates a position that is higher than something else, typically implying proximity or contact, or it can introduce a condition or circumstance.
The word "upon" originates from the Middle English "up on," which is a combination of "up" and "on." It has Germanic roots, similar to Old Norse "upp รก" and Old English "uppan."