You can deduct the payments if under $3,000 on your 2020 tax return as an itemized deduction, but that won't benefit you if don't itemize, which most people don't anymore.
Your other option is to recalculate your tax in the year the UI applies to and enter the benefit on your 2020 tax return as a credit (reduction of tax). Here is an quote from IRS Publication 525 that explains how to do it: