1099 income

All of my $12136 income for 2020 was from the Arizona state prison and was reported on a 1099.  No taxes were withheld.  I filed an information return to get my stimulus payment.  Since it was under the #12400 standard deduction, I did not show it.  My information return was rejected because I didn't actually request the rebate.  My uncle says that because the 1099 shows more than $600 that I have to report it as other income and pay self employment taxes on the full amount.  Which is correct?