错误信息：{ code: 'PARAM_ERROR', message: '$key0$参数格式错误' }

请求地址：https://apihk.mch.weixin.qq.com/v3/global/transactions/jsapi

请求参数：{"mchid":"666001732","appid":"wx89a3c358e3beafe8","notify_url":"https://ty.oiuyuai.com/v1/payment/wx/success","out_trade_no":"1720169778474Gmq","description":"助手充值","merchant_category_code":"4814","trade_type":"JSAPI","amount":{"total":50,"currency":"GBP"},"payer":{"openid":"oQM2g6a5w1ivqufwJOmTd5KsQ1S9"}}

支付商户是英国公司的信息注册的

提示参数格式错误，但是无法定位确切错误信息？望有经验的朋友给予解决方案