Until you pay it back, the income in includible on your 2020, 2021 and 2022 tax returns and will be taxed. IF you pay 1/3 back before the filing deadline including extensions, of your 2020 tax return, you will owe no tax on this money for 2020 but you'll still be obligated to report 1/3 on your 2021 tax return and 1/3 on your 2022 tax returns unless you pay those portions back before the due dates of those tax returns.
If you wait until 2023 (but still less than 3 years after the distribution) to make the repayment of the entire amount, you'll need to file amended 2020, 2021 and possibly 2022 tax returns to claim a refund of the taxes paid on the repaid amount.
