Order placement is made through the order form located on the right hand side of the trading interface
To place your order you need to select the
You can buy (long) or sell (short), to select the side use the tab system
You can enter the size both in base and quote currencies, the conversion in the equivalent amount will be made automatically
You can increase your leverage by using the slider
To send your order click on BUY/LONG if you want to buy or SELL/SHORT if you want to sell and approve the transaction.