Since this is not a business, and there is no 1099, I would put the $250 into Line 21 of Schedule 1. Do this by going to personal income/less common income/miscellaneous income/other reportable income. Click that you had taxable income. You should get to a page with 2 entries to enter data. For the "Description" enter something like School Psych Study. Then enter the amount. Check Line 21 of Schedule 1 to be sure the value went to the desired location in the return.
