It depends on what you define as the "ISS." The ISS as NASA defines it does not exist. The bright object flying through the sky, however, does in fact exist. One does not need to accept both.
Strawman argument. The existence of
any object at all behaving like a satellite, that is visible across most of the world to millions of people, many of whom cross check its transits in real life with those predicted and find they match, with a calculable altitude (see page 1 for maths) utterly destroys FET.
Run along, back under your bridge now.