method Deno.Env.get
Env.get(key: string): string | undefined
Retrieve the value of an environment variable.
Returns `undefined` if the supplied environment variable is not defined.
```ts
console.log(Deno.env.get("HOME")); // e.g. outputs "/home/alice"
console.log(Deno.env.get("MADE_UP_VAR")); // outputs "undefined"
```
Requires `allow-env` permission.
string | undefined