env.get(name, { otherwise }) the value, or otherwise (default null) when the variable is not set
Needs env:NAME for each variable read.
This script reads a variable that is set and one that is not.
allow: [env:HOME, env:LOG_LEVEL]
const home = env.get("HOME")
const level = env.get("LOG_LEVEL", { otherwise: "info" }) // gives "info"
return { home, level }