问题可复现

使用环境：微信h5中调用

支付分已完结的订单，申请退款时，使用外部商户订单号进行退款，会出现RESOURCE_NOT_EXISTS，订单不存在错误提示。

支付成功返回：

{
	"code": "200",
	"msg": "请求成功",
	"data": "{\"appid\":\"xxx\",\"mchid\":\"xxx\",\"service_id\":\"xxx\",\"out_order_no\":\"M20210712001\",\"service_introduction\":\"xxx租借服务\",\"state\":\"DONE\",\"state_description\":\"\",\"total_amount\":100,\"post_payments\":[{\"name\":\"租借费\",\"amount\":100,\"description\":\"0.01／分钟\"}],\"risk_fund\":{\"name\":\"DEPOSIT\",\"amount\":9900,\"description\":\"\"},\"time_range\":{\"start_time\":\"20210712162957\",\"end_time\":\"20210712163211\"},\"attach\":\"\",\"notify_url\":\"http://xxx/xxx/payScoreCallbackNotification.do\",\"order_id\":\"1000000000202107121390175710571\",\"need_collection\":true,\"collection\":{\"state\":\"USER_PAID\",\"total_amount\":100,\"paying_amount\":0,\"paid_amount\":100,\"details\":[{\"amount\":100,\"paid_type\":\"NEWTON\",\"paid_time\":\"20210712163213\",\"transaction_id\":\"4200001188202107123853641530\"}]},\"openid\":\"oSaGm6EJRRkZ30_US62dfR9Ps0rQ\"}"
}

//1.申请退款请求代码（out_trade_no）：
{
	"amount": {
		"currency": "CNY",
		"refund": 1,
		"total": 100
	},
	"notify_url": "http://xxx/xxx/refundCallbackNotification.do",
	"out_refund_no": "tk4wyp81811vqW003t17kA3F8g85u64ID7",
	"out_trade_no": "M20210712001",
	"reason": "手动退款"
}
//退款返回
{"code":"RESOURCE_NOT_EXISTS","message":"订单不存在"}

2.使用transaction_id进行退款是可以的

退款请求参数（使用微信支付单号transaction_id）: 

{
	"amount": {
		"currency": "CNY",
		"refund": 1,
		"total": 100
	},
	"notify_url": "http://xxx/xxx/refundCallbackNotification.do",
	"out_refund_no": "tk5rS72co70JA8080vt66638aR628979qI",
	"reason": "手动退款",
	"transaction_id": "4200001188202107123853641530"
}

退款返回：

{
	"code": "200",
	"msg": "请求成功",
	"data": "{\"mchid\":\"xxx\",\"out_trade_no\":\"NN1yXx4f68mvIoqIMs2wY7xxxxj0gPZx\",\"transaction_id\":\"4200001188202107123853641530\",\"out_refund_no\":\"tk5rS72co70JA8080vt66638aR628979qI\",\"refund_id\":\"50301608892021071210582812260\",\"refund_status\":\"SUCCESS\",\"success_time\":\"2021-07-12T16:36:59+08:00\",\"amount\":{\"total\":100,\"refund\":1,\"payer_total\":100,\"payer_refund\":1},\"user_received_account\":\"支付用户零钱通\"}"
}