On your 2018 return look for the IRS Form 8582. It will have your carry over losses to 2019. If your 2018 return does not have the 8582, then you don't have any carry over losses. Let's assume it does though.
In TurboTax 2019, you *must* select the option in Property Profile to indicate you have carry over losses from 2018. Then, and only then, will you be asked to enter those losses from the 2018 IRS Form 8582.