Was that $20 your only income? If so you have no need to file a tax return. Are you just trying to get the stimulus check? You could just use the non-filer site if you had no taxable income---unless you are being supported by someone else and are being claimed as a dependent. If you are being claimed as someone else's dependent you are not eligible for the stimulus check.
If you are not being claimed as someone else's dependent:
https://www.irs.gov/coronavirus/non-filers-enter-payment-info-here