photos – Is it possible to merge the films of two different iPhone?

I have the iPhone 7 and the iPhone XS Max and these two iPhones are on the same iCloud account, but have different camera bearings.

Is it possible to copy all the photos from the iPhone 7 into my XS Max camera? It would be great if I could keep all existing information and store it in chronological order.

Note: I do not use iCloud photos and I do not intend to pay for it.