Resident alien J1 research scholar without W2

Hi! I'm a  visa J1 Research Scholar holder since December 2019. Last year, I reported my taxes as a Nonresident alien using Glacier software, but this year the program considered me a Resident alien for taxes purposes because I have been living here for more than 2 years, so I can't use that program. I would like to know how I should report my income, I'm a postdoc, I received a monthly stipend, which is not a scholarship. I didn't receive a W2 or any official documentation. I'll appreciate any advice on this, thank you!