Once a bubble spawns on your board, you will now see a red trash can icon to the left of the other two buttons: tapping on this button will remove the bubble you have selected and grant you a coin in its place!

Keep in mind that if you let a bubble expire on its own, then you will not receive a coin.

Of course, you still have the option to burst the bubble to purchase the item inside using either Gems or, for some items, by watching an ad.