I'm self employed and deferred some of my 2020 taxes. However, I can't find the deferred amount. Where can I see how much tax was deferred and when its due?

When I filed my 2020 taxes (self-employed), I was asked if I wanted to defer some of the taxes we owed. Being short on savings, I agreed to the deferral. Now I can't find how much was deferred and when I'll owe it to the Fed. I want to plan on the amount I'll owe later, but need to know where to find that information.