Can we file amendment on RFE response

My Visa Status is F1 OPT Ext

I received RFE for my H1B new petition requesting for client letter.

Client letter is not received in due time and RFE response was submitted. After RFE is responded, received the client letter,

So in this case is it possible to file an amendment and submit the client letter.

Appreciate your inputs!

Regards, Dex.