Error while setup .env in CI

I am following the setps mentioned here.

but I am getting this error:

Fatal error: Uncaught TypeError: Argument 1 passed to Dotenv\Dotenv::create() must be an instance of Dotenv\Repository\RepositoryInterface, string given, called in C:\wamp64\www\ci\bootstrap.php on line 5 and defined in C:\wamp64\www\ci\vendor\vlucas\phpdotenv\src\Dotenv.php on line 62

Please help