Set an order with a fixed price in usdt example= Q=10(10usdt) on Binance usdm
At the moment, your commands execute with the contracts value that you set. To calculate your contracts based on your balance, you may use the percentage of your account. So lets say it is 10% of your balance 100USD, then that would be 10USDT.
It sure makes sense to have it based on value too. So that would be something interesting to have. Stay tuned.