how to complete the section "Report Regular Tax Carryover"?

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 to Less 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..

• How do I enter a capital loss carryover?

Please update with additional details if you need further assistance and we will help.