Strike Post replacement on Shower Door

I was hoping you could help me in finding out what I need to get or replace with my shower door and the part the holds the magnetic stripe to keep the door closed. I don't know what it is called as I have watched videos and read a bunch but hear different descriptions-strike post, door jamb, U-Channel etc.
I've attached pictures and video but cannot figure out what the attached metal part/piece is.

You will notice at the bottom of the part/piece, it is worn out/corroded and loose.

Any help is appreciated!