It is not a deduction from income. Rather, it is a credit against taxes due. If you owe no Federal taxes, the credit gives you no benefit.
We've still in the early part of 2021, so how do you know you won't have any income this year except for unemployment comp? That being said, if your 2021 income is low, you might consider generating more to offset that credit by converting a Traditional IRA to a Roth. But also keep any state income taxes in mind if you do.