This is very weird false positive. We do not have Ali Pay anywhere inside our product. We don’t have any references to it at all, on any platform.
My guess is AliPay has some symbols like “makePurchase” or other common word that we have too. You can respond to reviewer that your apps have nothing to do with AliPay and didn’t even stand close to that payment system. If they can point out why do they thing we have AliPay, that would be helpful, because it is hard to fix something we don’t have broken.
I am so sorry for this situation. But I am in same boat as you - I just don’t have any idea why apple believes we have AliPay.