Hello you are looking at the picture on your display – thus 96 dpi. To get the actual picture at the 300 DPI you need to know the physical size of the drawing – like a picture 300x300 pixel will have 300 DPI when drawn on a 1x1inc physical device/paper.
If your drawing will be 5x5 inch – you need 1500x1500 pixel image size to make it 300DPI
Best wishes.
