It depends. If the cost basis for the trade was reported to the IRS, then you won't have to amend. If the cost basis was not reported to the IRS then they will assume the entire proceeds is a gain, and you might need to amend.
How do I know if it was reported to the IRS? I bought stock on Robinhood in March but sold it by summer and kept all the funds on my Robinhood account.
i would call irs after you receive your refund and ask you might be able to file this on 2021 taxes you have 3 years to amend
if you didn't report it via turbotax when you e-filed its not reported i would wait till you receive your refund then amend.like i said you have 3 years to amend
but with it being so little it might not even be worth it i would not worry about it tbh since its under 500