src/ACFProInstaller/Plugin.php
protected function getKeyFromEnv()
    {
        $this->loadDotEnv();
        $key = getenv(self::KEY_ENV_VARIABLE);

        if (!$key) {
            throw new MissingKeyException(self::KEY_ENV_VARIABLE);
        }

        return $key;
    }
protected function getKeyFromEnv()
    {
        $this->loadDotEnv();
        $key = getenv(self::KEY_ENV_VARIABLE);

        if (!$key) {
            throw new MissingKeyException(self::KEY_ENV_VARIABLE);
        }

        return $key;
    }
protected function getKeyFromEnv ( ) { $ this -> loadDotEnv ( ) ; $ key = getenv ( self :: KEY_ENV_VARIABLE ) ; if ( ! $ key ) { throw new MissingKeyException ( self :: KEY_ENV_VARIABLE ) ; } return $ key ; }
Get the ACF PRO key from the environment

Loads the .env file that is in the same directory as composer.json
and gets the key from the environment variable KEY_ENV_VARIABLE.
Already set variables will not be overwritten by the variables in .env
@link https://github.com/vlucas/phpdotenv#immutability

@access protected
@return string The key from the environment
@throws PhilippBaschke\ACFProInstaller\Exceptions\MissingKeyException
Get the ACF PRO key from the environment