Why order pending list not working?

[dragonball9816]

I don't know why orderpending/orderPendingList not working.
My sample is as following:

url: https://api.bibox.com/v1/orderpending
cmds: [{"cmd":"orderpending/orderPendingList","body":{"pair":"ETH_BTC","account_type":0,"order_side":0,"coin_symbol":"ETH","currency_symbol":"BTC","page":1,"size":10}}]
apitkey: xxxxxxxxxxxxxxx
sign: xxxxxxxxxxxxxxxxx

That result is as following:

{"result":[{"cmd":"orderpending/orderPendingList","result":{"count":10,"items":[],"page":1}}]}

I get only empty array for open orders list.
What is the problem?
Please help me.