What is a stop-loss order?
A stop loss order is an order placed to buy or sell a stock when it reaches a certain price. The stop loss order is primarily meant to limit your loss on a stock that you have already purchased.
The price you mention in the stop-loss order is the highest risk (losses) that you are ready to take on that stock. It can be a limit order or a market order.
You can read more about stop-loss orders here.
To place a stop loss limit order you will need to select SL Lmt in the order type section. You will also need to enter the Price and the Trigger price when you are placing this order.
To place stop loss market order you need to select SL Mkt in the Order type section and enter the Trigger price.