以下是我的分账代码

public static function profitSharing($transaction_id,$amount)
{
    // 商户相关配置，
    $merchantId = config('wechat.wechat_mch_id'); // 商户号
    $merchantSerialNumber = '2278A992C067DCE19C8328B027B6B41D90DC2349'; // 商户API证书序列号
    $merchantPrivateKey = PemUtil::loadPrivateKey(config_path().'/cert/apiclient_key.pem'); // 商户私钥文件路径

    // 微信支付平台配置
    $wechatpayCertificate = PemUtil::loadCertificate(config_path().'/cert/wechatpay_platform.pem'); // 微信支付平台证书文件路径

    // 构造一个WechatPayMiddleware
    $wechatpayMiddleware = WechatPayMiddleware::builder()
        ->withMerchant($merchantId, $merchantSerialNumber, $merchantPrivateKey) // 传入商户相关配置
        ->withWechatPay([ $wechatpayCertificate ]) // 可传入多个微信支付平台证书，参数类型为array
        ->build();

    // 将WechatPayMiddleware添加到Guzzle的HandlerStack中
    $stack = \GuzzleHttp\HandlerStack::create();
    $stack->push($wechatpayMiddleware, 'wechatpay');

    // 创建Guzzle HTTP Client时，将HandlerStack传入，接下来，正常使用Guzzle发起API请求，WechatPayMiddleware会自动地处理签名和验签
    $client = new \GuzzleHttp\Client(['handler' => $stack]);
    //$pay_time_expire_minutes = env('TIME_EXPIRE');
    //$time_expire = Carbon::parse('+'.$pay_time_expire_minutes.'minutes')->toW3cString();

    $header = array(
        "Content-Type: application/json",
        "Accept: application/json",
        'Content-Type: application/json; charset=utf-8',
        'User-Agent:Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36',
        'Expect:',
    );

    $out_order_no = 'P'.orderNO(mt_rand(0,99));
    $receiver = array(
        'type' => 'MERCHANT_ID',
        'account' => '1614276273', // 爱尔福文化创意咨询商户号
        'name' => '',
        'amount' => $amount, // 分账金额，单位为分，只能为整数，不能超过原订单支付金额及最大分账比例金额
        'description' => '分给商户爱尔福', // 分账描述
    );
    $param = array(
        'appid' => config('wechat.wechat_small_appid'), // appid
        'transaction_id' => $transaction_id, // 微信订单号
        'out_order_no' => $out_order_no, // 商户分账单号
        'receivers' => [$receiver], // 分账接收方列表
        'unfreeze_unsplit'=> true, // 是否解冻剩余未分资金
    );

    Log::info('请求分账:');
    Log::info(json_encode($param));

    try {
        $resp = $client->request(
            'POST',
            'https://api.mch.weixin.qq.com/v3/profitsharing/orders', //请求URL
            [
                // JSON请求体
                'json' => $param,
                'headers' => $header
            ]
        );
        $statusCode = $resp->getStatusCode();
        Log::info(json_encode($resp));
    } catch (RequestException $e) {
        // 进行错误处理
        $msg = $e->getMessage()."\n";
        $code = 10001;
        Log::info(json_encode($e));
        if ($e->hasResponse()) {
            $code = $e->getResponse()->getStatusCode();
            $msg = $e->getResponse()->getBody();
        }
        $ret = [
            'code' => $code,
            'msg' => $msg,
        ];
        Log::info(json_encode($ret));
    }
}