Your MT4 charts display the bid (sell) price in the market. However, when you are in a short (sell) position, then it is the ask (buy) price that must reach your take profit level.
We believe the way you say it makes it more complicated. Try to think of it in the following way:
If you buy to open a trade, then you must sell to close it. That means you enter at the ask price (which is the chart price plus the spread) and exit at the bid price (which is the chart price).
If you sell to open a trade, then you must buy to close it. That means you enter at the bid price (which is the chart price) and exit at the ask price (which is the chart price plus the spread).
Either way you pay the spread only once. When you look at the chart, what matters is whether you are interested in the buy price or the sell price.
If you want to know the buy price, then you must add the spread. If you want to know the sell price, then you don’t need to add anything to the chart price you see.
The closest functionality to this built into the MT4 platform is the option to “Show Ask line”.
Right-click on your chart.
Select “Properties” from the pop up menu.
Check the box that says “Show Ask line” and hit OK.
That will show the current Ask price in the market with a horizontal line on your chart.