There are a few ways this can be achieved. The Red highlights below indicate the “New Order” buttons which can be used to open a trade. You can Drag in limit orders using the buttons indicated at the top of the screen. Just drag this onto the chart where you would like the order to be placed and this will open a Limit order for you at that price.
Finally using the “Active Symbol Panel” you can place trades using this panel on the current instrument you have selected.