Where can I find the bottom case screws with the shoulders on them

Hello, I have a mid 2012 MBP 13” A1278 computer, and I am missing two the case screws that have shoulders on them, as this computer requires a total of 4 screws with shoulders on them.

I looked on the ifixit store and apparently there is no mention of screws with shoulders on them.

MacBook Pro Unibody Lower Case Screw Set

However when I am looking at one of the teardowns for the 13” MBP A1278 mid 2012 there is clear picture describing three different types of screws.

Remplazo de la Placa Lógica del MacBook Pro Unibody Mediados de 2012 de 13"