2021-11-20 16:01:03[1637424063.1479] - new buy order: Array
(
    [contract] => DOT_USDT
    [price] => 40.1727
    [size] => 0
    [tif] => gtc
)
 Array
(
    [label] => INVALID_ARGUMENT
    [detail] => invalid size
)

2021-11-20 19:01:03[1637434863.9563] - new buy order: Array
(
    [contract] => DOT_USDT
    [price] => 41.7047
    [size] => 0
    [tif] => gtc
)
 Array
(
    [label] => INVALID_ARGUMENT
    [detail] => invalid size
)