You can report it as “Other Employment Income”. Click
“Find” and search for “Employment Status” (you may need to scroll down), then
select it from the list and click on the “Go” button.
Check off “Received tips, gratuities, occasional
earnings, or other employment income”, then click the “Continue” button.
On the “Other Employment Income Sources” page, fill in
the top line, “Tips, gratuities or occasional earning not reported on a tax
slip from the payer”, then click the “Continue” to save your changes.