If you are referring to the Key Editor in the Project Window’s Lower Zone, then activate the button in the Lower Zone labeled “Link Project and Lower Zone Editor Cursors” - it looks like 2 links in a chain. If you can’t see the button use the gear configuration button to make it visible.
If you want to align the Key Editor in its own floating Window & the Project Window, you can’t. They are totally independant of each other and can be different sizes and shapes