Please explain what you mean. Are you saying you did not file a 2018 return at all and thus did not report any income for that year? Or are you saying you don't know the 2018 AGI from your 2018 return and don't know how to get it?
Did you use Online TurboTax for a 2018 return?
You didn't place anything in context, but I presume you are inquiring in regard to efiling a 2019 return, which is asking for a 2018 AGI or a prior-year Self-Select PIN. We can tell you what to do once you answer the questions above.
