Per 2020 Delaware Form 200-01 Instructions page 10, the adjustment to not tax Federal Unemployment is done on Line 36 as a Fiduciary Adjustment.
To do this in TurboTax, during the state interview for Delaware, when prompted to Enter Your Total Other Exclusions, enter Unemployment compensation as a negative number. For example, Unemployment compensation of 5,000 is removed from Delaware by entering -5,000 for this adjustment.