function main() {
exchange.IO("currency", "BCH_USD") //设置合约币种
var ret = exchange.IO("API", "POST", "/api/v4/futures/btc",'"contract":"BCH_USD","size":1,"price":"100","close":false,"tif":"gtc","text":"web"')
return ret
}

我用以上自编写的代码exchange.IO下单Gate时，一直返回Futures_OP 4: 404: {"label":"NOT_FOUND"} 或者 Futures_OP 4: argument error 报错，估计是程序格式或参数问题，求大神打救！！给个Gate的标准范文也行~~

Gate.io的API期货订单文档显示如下：
Body parameter
{
"contract": "BTC_USD",
"size": 6024,
"iceberg": 0,
"price": "3765",
"tif": "gtc",
"text": "t-my-custom-id"
}