求助：为何 分账接收方格式错误

请求接口：

//请求URL
String url = "https://api.mch.weixin.qq.com/pay/profitsharingaddreceiver";

请求参数如下：

"<xml>

<appid>wxec72c6ba2f9e427c</appid>

<mch_id>1646523746</mch_id>

<nonce_str>nvSnHhXwrN8QnC7P82RRq73SGst3j7cw</nonce_str>

<sign>01CD8D40AF3CEBD37DC45CADDDBB97D2</sign>

<receiver><![CDATA[{\"name\":\"佛山市餐饮管理有限公司\",\"relation_type\":\"STORE\",\"type\":\"MERCHANT_ID\",\"account\":\"1722227523\"}]]></receiver>

</xml>"

返回参数如下：

"<xml>

\n<return_code><![CDATA[FAIL]]></return_code>

\n<return_msg><![CDATA[分账接收方格式错误]]></return_msg>

\n</xml>"

代码如下：

// 使用新的支付商户号

        String mchId = "1648888746";

        String mchSerialNo = "538F3EEF7BA2678888888888888888497926293E";

        String fileName = "kpsmy2.pem";

        String apiV3Key = "ASDfghj8888888888888iop123456"; // V3密钥 ASDfghjklz99999999999999999923456

        //请求URL

        String url = "https://api.mch.weixin.qq.com/pay/profitsharingaddreceiver";

        String nonce_str = getRandomString(32);

        String timeStamp = String.valueOf((System.currentTimeMillis() / 1000)); // 十位时间戳

        JSONObject receiver = new JSONObject();

        receiver.put("type",type);//"MERCHANT_ID"

        receiver.put("account",account);//"1700827523"

        receiver.put("name",name);//"佛山市管理有限公司"

        receiver.put("relation_type",relation_type);//"STORE"

//        receiver.put("custom_relation",custom_relation);

        String uri = System.getProperty("user.dir") + "/" + fileName;

        PrivateKey merchantPrivateKey = getPrivateKey(uri);

        Map<String, String> data2 = new HashMap<>();

        data2.put("mch_id", mchId);

        data2.put("appid", appId);

        data2.put("nonce_str", nonce_str);

        data2.put("receiver",receiver.toJSONString());

//        data2.put("sign_type", "HMAC-SHA256");

        String paySign = WXPay1Util.generateSignature(data2, apiV3Key); //MD5加密

        String xml ="<xml>" +

                "<appid>" + appId +"</appid>" +

                "<mch_id>" + mchId +"</mch_id>" +

                "<nonce_str>" + nonce_str +"</nonce_str>" +

                "<sign>" + paySign +"</sign>" +

//                "<sign_type>HMAC-SHA256</sign_type>" +

                "<receiver><![CDATA["+receiver.toJSONString()+"]]></receiver>" +

                "</xml>";

        System.out.println(JSON.toJSONString(xml));

        String result = "" ;

        try {

            result = HttpRequest.post(url)

                    .body(xml)//表单内容

                    .timeout(30000)//超时，毫秒

                    .execute().body();

        }catch (Exception e){

        }

        System.out.println(JSON.toJSONString(result));