To add ATR , right click on volume chart (where your arrow is pointing) then right click and select "Study Config."
Click ATR from "Studies" column and move it (Select-->) so it's placed in the "Studies in Chart" column.
Click ATR in "Studies in Chart" column and Config (enter # of periods you require - default is 14). Then click "Commit".
Again, right click on volume chart (where your arrow is pointing) and select "Chart Area" and select " Config Area" (bottom of list).
Check " Show Study Info" and "Show Study Latest Value" then "Commit".
Your ATR values should now be displayed.