Thank you for your reply!
Oh no, I only mailed 1040x form.
I guess I will receive the request letter for additional doc but I wonder I can already mail in because
it took 10 days to get to the IRS office in CA from HI because of Covid.
Is there any particular rule to send additional documents to file after you mailed in 1040x, before receiving a letter from IRS? I searched a bit but could not find any...
