api调用中文会出现乱码，可以解决一下吗？

[app4v]

let body=JSON.stringify([ { "clientId": 1, "plateNo": "浙A111111", "plateType": "1", "plateColor": "1", "vehicleType": "0", "vehicleColor": "0", "description": "test" } ] ); let httpRes=await Hikopenapi.httpPost(requestUrl+"/api/resource/v1/vehicle/batch/add",headers,body,appKey,appSecret,timeout); const buff = Buffer.from(JSON.parse(httpRes).data, 'base64').toString('utf-8'); console.log(buff); 　//{"status":true,error:0,data:""}
车库号码中的‘浙’会变成乱码。