To set a pending order on desktop MT5, please follow the steps below:
Right-click an instrument you want in the market watch window.
Go to "New Order"
In the next window, set the desired instrument and set the "order type" to "Pending order."
A new list will appear asking you to choose the order type, such as Buy limit, Sell stop ...
Set the price you want your order executed at.
Set the volume of your order.
You can also set your take profit and stop loss levels.
Click "Place" to set the pending order.