回複：thank you so much for reply!

the case is: U.S. citizen as the petitioner, spouse of the U.S. citizen is the applicant (beneficiary). Beneficiary is in U.S.
-You can file your I-485 now or anytime you want to.

I don't have a photocopy of the approval letter. Do I absolutely need the approval notice?
-You need to provide a photocopy of the I-130 approval notice when you file I-485. So, you need to get the duplicate as the USCIS officer suggested.

Thanks a lot for your kindness!!