number of decimal units that the okex perpetual contract cannot open

If you order a contract for a number of 0.123, it will return an error, suggesting that it is a whole number unit?

I'm using the API v5 type.

It's like you have to write down the number of integers.

2021-07-23 09:45:40 Futures_OKCoin was not found

Sell(-1, 0.126): map[code:1 data:[map[clOrdId:9e7f8f03cd7548BCbbc2BD64F76B3F93 ordId: sCode:51121 sMsg:Order count should be the integer multiples of the lot size tag:]] msg:]

Buy(-1, 0.126): map[code:1 data:[map[clOrdId:9e7f8f03cd7548BCbbc0EF26A5F0BD45 ordId: sCode:51121 sMsg:Order count should be the integer multiples of the lot size tag:]] msg:]