It's very simple to enter a capital loss carryover in the program.
Go to the Federal Taxes tab,
Wages and Income,
Scroll down to Investment Income
Start or Update the second topic Capital Loss Carryover
Since you know the total amount of your carryover, say Yes, you know your amounts
Enter the TOTAL amount of your carryover loss, not just the $3,000. The program will automatically carry that over to the AMT fields.
You can also just type the words capital loss carryover into the Find box on the upper right,
then select the Jump To below.