I’m not sure what the letter requires but it seems like some people are saying you may need last years AGI but all the information from last year is able to be downloaded or opened on a smart phone but easier to see on a laptop. I was reviewing my 2017 tax return last night. I also went to irs.gov and in the search bar typed in Secure Access and registered an account with my information and I used the last 8 digits of one of my credit cards. The other options were information about a home loan or a student loan I didn’t have any of that information so I used the only thing I have which was a credit card no debit cards but I had accesss to all prior years tax info. I hope that helps
