Please select your situation and follow the path-

If you have a Form W-2G, go to: 

1.  Sign into your TurboTax online account and select Take me to my return

2.  At the right upper corner, in the search box, type in W2g and Enter

3.  Select to Jump to W2g and follow the prompts

4.  On screen, Tell Us About Your Winnings, select Enter A W-2G and enter information

5.  Follow step-by-step interview questions, on screen Gambling Losses, enter the amount.

If you DO NOT have a Form W-2G, go to: 

1.  Sign into your TurboTax online account and select Take me to my return

2.  At the right upper corner, in the search box, type in W2g and Enter

3.  Select to Jump to W2g and follow the prompts

4.  On screen, Tell Us About Your Winnings, select Skip W-2G and enter information

5.  Next screen, Any Other Gambling Winnings, answer Yes and follow prompts

6.  Next screen Gambling Losses, enter the amount.