Apon feels like a misspelled Edition of "apron". If you are not referring to cooking have on, it's "upon".
the proper phrase is "on us." for instance, "Winter is upon us" or "The deadline is on us." This usage of https://adreaxnsd616390.aboutyoublog.com/31213356/the-smart-trick-of-apon-that-nobody-is-discussing