First Open Nitro and click the “Review” tab.
Then click the arrow below stamp and click “Create New Stamp” at the bottom.
After this window will come up, in the dropdown by “Text” select “Approved” then click “Include name, date and time”. Make the colour green and same the Width and Height a decent size like shown below. When finished click “OK”.
After right click the stamp Icon and click “Add to Quick Access Toolbar” so it allows so easy access you can find it in you quick access bar usually at the top right of the window.