How to Undo or Redo a particular change?
You can undo or redo a change with the undo and redo buttons are given on the top of the right panel.
Or you can also use your keyboard shortcuts:
Windows: CTRL + Z to undo | CTRL + Y to redo
Macbook: CMD + Z to undo | CMD + Y to redo
Note: The redo button will only appear after you have undone a change