Once you have opened the tool and added it to your board, you can change the size of the square and drag it around. Click on the square to reveal your set feedback.
Go to Settings (gear icon in the bottom left corner of the tool) to change the properties of the tool. You can choose if the square indicates a correct or incorrect answer. You can also change the type of frame shown, including a green or red frame, an icon (green checkmark or red x), or an emoji (happy or sad). You can also choose to play a sound effect when the answer is revealed.