If you were a nonresident alien for tax years 2017 and 2018 you need to file a Form 1040NR.  TurboTax does not support Form 1040NR.

See this TurobTax support FAQ for information - https://ttlc.intuit.com/community/forms/help/does-turbotax-handle-form-1040nr-for-nonresident-aliens...

TurboTax cannot prepare returns for non-resident aliens, since it cannot prepare Form 1040NR/NR-EZ.   TurboTax has an affiliate partner Sprintax (one "t) that specializes in non-resident returns for international filers  (see the FAQ that DoninGA provided in his comment above).

I can ask someone familiar with international filing to further advise.  Please answer the following:

• So you are not a USA citizen, correct? 
• What country are you from?
• When did you first come to the USA, and how long have you been here?
• What kind of visa were you under those years 2017 and 2018 and subsequent years?
• Are you married?

 @ pk  Are you able to please continue helping the user in this thread when you are next in the forum?  Thanks!