Board Game Arena

Playing my first game and I can't figure out how to discard.

When is discarding possible and what do you click to do it?
All that ever seems available is to draw a card, place a card on the 'clock' or pass, even though I have cards into in my hand that haven't been discarded yet.

Thanks!

You need to have three copies of the same number to "discard" them.

Oh, thanks!