It depends. If it is a net operating loss (NOL) carryover you can report it as follows.
For TurboTax Online: Under Income and Expenses Scroll to Other Business Situations > Select Net Operating Loss/QBI Carryforward Loss
For TurboTax Desktop > Business Income and Expenses > Scroll toLess Common Business Situations section (click Start to the right of Net Operating Loss/QBI Carryforward Loss).
If it is a capital loss carryover you can enter it using the link below..