我遇见的是签名的方式不对，我参考是 demo  wechatpay-java
com.wechat.pay.java.service.partnerpayments.jsapi.JsapiServiceExtension #prepayWithRequestPayment

{
    "code": 400,
    "msg": "ERROR_GATEWAY: Get Wechat API Error:AppID不存在，请检查后再试",
    "data": {
        "config": {
            "order": {
                "attach": "花有有",
                "body": "花有有-订单支付",
                "out_trade_no": "20220616967014",
                "total_fee": 3,
                "sub_openid": "o5HFE5BasfCs2HGuEeMr2QDvK6d0"
            },
            "configs": {
                "app_id": "wx65439739882e0afe",
                "sub_miniapp_id": "wxa5f23718ce751a25",
                "mch_id": "1621146496",
                "sub_mch_id": "1626917369",
                "key": "asdfghjklzxcvbnmasdfghjklzxcvbnm",
                "profit_sharing": "Y",
                "mode": "service",
                "notify_url": "http://www.yiquhuashang.com/api/v1/verify/order",
                "log": {
                    "file": "./logs/wechat.log",
                    "level": "debug",
                    "type": "single",
                    "max_file": 30
                }
            }
        }
    }
}