问如何在Kotlin中使用协程和改进从代码为400的服务器响应中获取正文？

EN

{"message": "User was created."}

@POST("api/user/createUser.php")
suspend fun register(@Body details : JsonObject) : Response<JsonElement>

val service = Server.ApiClient.createService(ServerInterface::class.java)
        
        CoroutineScope(Dispatchers.IO).launch {

            try {
                val response = service.register(details)
                Log.wtf("Message",response.body().toString())
            }
            catch (e : Exception){
                Log.wtf("Error",e.message)
            }
        }

E/Message: {"message":"User was created."}

E/Message: null