`export` - set an export attribute for shell variables

export [-n] [NAME[=VALUE]]...

Options you will use

-n: Remove the export attribute.
-p: List all exported variables.

Gotchas

Without export a variable exists only in THIS shell; child processes never see it.

Taught in

15.3 The speed kit, and the shape of every kubectl command

Try export in a real terminal Free, in your browser - a real Ubuntu terminal to try it in, with missions that check your work.