Those movies were sequels to the original *Home Alone* (1990) featuring Culkin, but different child actors were cast for those films.
* Home Alone 3 (1997) starred Alex D. Linz as Alex Pruitt.
* Taking Back the House (1999) was a direct-to-video release and featured Michael O'Neill as Kevin.
It's understandable that you might think Culkin was in those movies, as they were marketed as *Home Alone* sequels, and they followed a similar premise. However, Culkin decided not to reprise his role in the sequels.