Some things that may be helpful to others in the future to get it working I had to install:
composer require vlucas/phpdotenv
composer require phpoption/phpoption
Works well 😀 just to work out how to register and all sorted, thanks for the plugin.
Spoke to soon, it suddenly started failing:
Uncaught Dotenv\Exception\InvalidPathException: Unable to read any of the environment file(s)