Looking at the Market Depth window you can see the trades that are available at the moment within the PrimeBit platform.
You can easily open a pending order with this feature.
First, set the volume. Then you can use the arrows on the buy (blue) and sell (red) sides of the market to set:
After clicking one of the "^" arrows a pending order window will pop-up.
Use it to set the pending order and press the "Place" button.