I'm confused: "Other than amending the 2019 return"

"The covered period for making loans was initially the period beginning on February
15, 2020 and ending on June 30, 2020. See section 1102(a)(2) of the CARES Act. The
Paycheck Protection Program Flexibility Act of 2020, Pub. L. No. 116-142, 134 Stat. 641
(June 5, 2020), extended the end date of the covered period for making loans from June
30, 2020 to December 31, 2020."

"Please provide support for your answer."

Rev. Rul. 2020-27