path-key 
Get the PATH environment variable key cross-platform
It's usually PATH, but on Windows it can be any casing like Path...
Install
$ npm install path-key
Usage
const pathKey = require('path-key');
const key = pathKey();
const PATH = process.env[key];
API
pathKey(options?)
options
Type: object
env
Type: object
Default: process.env
Use a custom environment variables object.
Type: string
Default: process.platform
Get the PATH key for a specific platform.