SocialiteProviders\Manager\Helpers\ConfigRetriever::fromEnv PHP Method

    public function fromEnv($providerIdentifier, array $additionalConfigKeys = [])
    {
        $this->providerIdentifier = $providerIdentifier;
        $this->additionalConfigKeys = $additionalConfigKeys;
        return new Config($this->getFromEnv('KEY'), $this->getFromEnv('SECRET'), $this->getFromEnv('REDIRECT_URI'), $this->getConfigItems($additionalConfigKeys, function ($key) {
            return $this->getFromEnv(strtoupper($key));
        }));
    }