It doesn't have to be repaid; that's a CARES Act Provision, not a requirement.

If the distribution is taxable, the 8915-E includes the option to pay the tax on the full amount in 2020 or to defer that into thirds.

If you repay any of it in 2012 or 2022, the repayment amount would be applied starting with the 2020 taxable amount and allocating it to each amount you reported and paid tax on already (these will be tax years you amend, after the fact) because you are no longer required to be taxed on that amount. The covid disaster declaration includes the three-year window as if that is a rollover provision.

This is a different provision than the waiver of the 10% early distribution penalty.