Mac users like to customize most features as the operating system has a huge capability for innovative techniques. You might want to check out the system preferences by typing an application, however, some keyboards lack a dedicated key for the backslash, known as Reverse solidus [\] on a MAC keyboard. A way to know how to type it using a combination of characters is by holding the alt + caps + / keys that solve the puzzle.
The backslash is a computer keyboard key [\] confused for a regular slash. There are various keyboard-remapping programs available on the internet to find the technique of creating a back slash for MacOS.
They work with nearly all models of MacOS computers. There are various other keyboard combinations for Mac users all over the world due to its global usage.