what does the notice say to do if you disagree. follow those instructions.
if it gives the option prepare a 1040 x with only the 8949's/schedule d. send it with the notice to the address indicated. include a signed and dated cover letter explaining the amended return now reports the omitted crypto proceeds and their tax basis. Ask that the IRS correct its records accordingly and send me a revised bill.
if you do mail it, use a tracking service so you know that the iRS got it
