Click on the bar so the box is on the bar number, while entering the chord it chows in the 'chord entry box' at top of chord window, it doesn't appear in the bar until you hit enter. It may appear like you can't enter chords, but you can. It just doesn't show in the bar until you hit enter key.

To see the other bars, use the scrollbar on right side of chords window

I do not work here, but the benefits are still awesome
Make your sound your own!