Overtrue\Socialite\Providers\WeChatProvider::getCodeFields PHP Method

    protected function getCodeFields($state = null)
    {
        return array_merge(['appid' => $this->clientId, 'redirect_uri' => $this->redirectUrl, 'response_type' => 'code', 'scope' => $this->formatScopes($this->scopes, $this->scopeSeparator), 'state' => $state ?: md5(time())], $this->parameters);
    }