Free Action Rules have "Free Action" printing in bold on the card.

When a rule states you can do something as a free action, that means you can do the action and it doesn’t cost any plays.

Most free actions can be taken at any time on your turn: before you draw, in the middle of your plays, or after all your plays are done.

If a player forgets to take a free action, they have until after the next player has drawn on their first card before it is too late.