I never said he wrote any of it. His administration did. Just like Biden never outright write the legislation he approves, because his own administration writes that. It's written by someone else, and Presidents are the ones that approve it.
It's his approval of this legislation, whether directly or through indirect coaxing and/or lack of disapproval (which for a President is an important factor), that makes him massively at fault for the Federal legislation that was signed through during his term.