legislation passed by Congress...Trump himself, in 2019, called on Congress to FINALLY resolve those problems but couldn't get even his own party to support billions for a Wall, so it never happened on his watch...but, Biden did strike a bipartisan deal in the Senate, which Trump then killed (Note: H.R. 2 out of the House was centered on the DOA 'Wall').
Biden delivered...Trump CHOSE not to...just so he could blow a dogwhistle in your ear.
If you really, really care about Border Security and a positive outcome on Immigration, you have to vote for Harris....otherwise you're making a foolish mistake.