They usually say Nihon instead of Nippon.

Some English used to use words derived from nippon as well but they mostly dropped out of the language not too long after WWII, prob bc nip is an old slur for Japanese people. There’s an ee cummings poem that refers to a piece of “nipponized steel”.

https://allpoetry.com/poem/13587560-plato-told-by-e.e.-cummings