2020 Back Unemployment Benefits received in 2021

I received the majority of my 2020 unemployment benefits that were owed to me in a lump sum in January 2021.  Is there any way I can use the $10,200 exemption that was meant for 2020 benefits, or am I stuck with no exemption because they were finally paid out to me in January 2021?

 

Thanks for any help you can offer!