My situation is as follows: In 2017 I've received an ~$18k income from US sources while living in Ireland (also I'm not a US citizen and was not a US resident at that time).
I have moved to US since (2019) and filed US tax returns for 2019 and 2020.
I have just received the notification from IRS that I have a "missing" tax return from 2017. Was in my situation I supposed to file a return in US even though I was not a US tax resident?
If so, do I need to file a 1040NR
form now for 2017? What is a good software to do that? (TurboTax, FreeTaxUSA don't seem to support filing 1040NR =)
Also looking at the form 1040NR now - how do I answer questions about residence/etc. Do I specify the information that was true as of 2017 or information that is true now?