How to update iOS on my iPhone 6s?

Hi there, wisdom281. Please remember - this is a community forum. It is not a chat service so you may not get an answer as quickly as you would like. Your iPhone 6s can only be updated to 15.7. Please try this - on your phone, select Settings > General > Software Update. If your iPhone is eligible for an update, you will be prompted to do so.

iPhone 6s cannot be updated to iOS 16 if that might be what you are asking about.