You should have a W-2G with reported winnings. You can use the steps here below to help you enter those casino winnings from that form.
- Log into your return by clicking orange Take me to my return button
- Type W2G in the Search box in the top right
- Click on jump to W2G and that will take you right to that section of the interview
- Choose Yes on the paged labeled Gambling Winnings and follow prompts to enter your W-2G