The new tax law eliminated the deduction for personal theft losses (which includes fraud) for 2018. You'd have to do an amended return for the year in which the loss occurred. You can't use an online version of TurboTax to do a previous year's return. If you wanted to use TurboTax you'd have to purchase the previous year's CD/Download version.
https://turbotax.intuit.com/personal-taxes/past-years-products/
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
