question about order volume for linear swap

[xmiraclez]

Hello. I try place this order:

order.isolated_order({'contract_code':'BTC-USDT','direction':'buy','pair':'BTC-USDT','volume':1,'contract_type':'swap','lever_rate':1,'order_price_type':'limit','price':10000,'offset':'open'})

and receiving:
{'status': 'error',
'err_code': 1047,
'err_msg': 'Insufficient margin available.',
'ts': 1657916879553}

so. 1 BTC is too large of course for my balance.

But if volume less 1 (0.01):

{'status': 'error',
'err_code': 1067,
'err_msg': 'The volume field is invalid. Please re-enter.',
'ts': 1657917373278}

How place order for small amount BTC?