I don't remember if I deferred self-employment tax in 2020. How can I know by looking at my return?

[VolvoGirl]

The self employment tax deferral was an optional benefit. It is also a deferral rather than forgiveness, so those amounts will eventually need to be repaid. Half of the deferred amount is due on December 31, 2021, and the other half is due on December 31, 2022.

Check if you have a Schedule 3 line 12e which goes to 1040 line 31.

How to pay the deferred self employment tax
https://www.irs.gov/newsroom/how-self-employed-individuals-and-household-employers-repay-deferred-so...