8915-E Instructions. Page 10.
"Enter on line 18 the amount of any
repayments you made before filing your
2020 return. Do not include any repayments
made later than the due date (including
extensions) for that return nor any
repayments of nontaxable amounts. If you
elected to spread the income over 3 years
and you repaid more than the amount on
line 17, the excess will be carried forward to
your 2021 tax return."
