Where is KEY SQUARES button?

On https://www.chess.com/lessons/view/6400 + START, it says " Click the KEY SQUARES button to see all the squares it can move to." 

Where is the KEY SQUARES button?

--Gil

Below and to the left of Show Hint.

That's the little light bulb, right?

Hmm.  I don't see it:

Maybe I have some Preference set wrong?

--Gil

In the browser version, clicking on the bishop highlights the square on which the bishop sits, preparing for you to then click on a destination square.  A second click turns off the highlighting.  A double-click does the same thing as two successive clicks.

Could there be a bug in the browser cgi?  Is there a procedure to report bugs?

--Gil

I found it!  Well, not IT, exactly, but a functionally equivalent analog.  Next to the upper-right corner of the board, just to the right of the board, is a little double-arrow...

...If you hover over that icon, meant to resize the board, then two more icons (not shown) will appear right under it.  The bottommost of these is a gear icon.  Click on the gear -- et voila! -- a menu (shown) appears.  the bottom choice on the menu sets up so that when you click on the piece, then THAT highlights the "key squares", the squares to which the bishop can move.

Not exactly the same as clicking a "KEY SQUARES button", but a serviceable analog.

Thanks, guys, for your persistence.

--Gil

It looks like the "Key Squares" button is not on the new chess.com site. Click on "Old Site" on the left menu to get to the old site and you will see the actual key squares button along with some others.