It depends. Where you enter a passive loss carryover depends on the activity that generated the passive loss.
For instance, if the passive loss was carried over from a Rental Property, you would enter the carryover for that property in the interview for the Property Profile.
If the passive loss was carried over from another investment, you would enter the carryover amount under Business Items during the interview for the Schedule K-1.
The easiest way to find the appropriate section of TurboTax is to go to My Account >> Tools >> Topic Search. Type in "passive loss carryover", then click the topic in the list that applies to go directly to the start of that section.
Look for a question like "I have passive activity losses carried over from last year." Check the box and TurboTax will ask you for the carryover amount later in the interview.
Note, however, if you have not reported passive losses on prior year tax returns, you would need to file an amended return for every year in order to claim those losses in that year. You can amend only for the last three tax years. Read more here: Do I need to Amend?