Researchers want the public to test themselves: https://yourmist.streamlit.app/. Selecting true or false against 20 headlines gives the user a set of scores and a “resilience” ranking that compares them to the wider U.S. population. It takes less than two minutes to complete.
The paper
Edit: the article might be misrepresenting the study and its findings, so it’s worth checking the paper itself. (See @realChem 's comment in the thread).
How can you tell which answers were which?
Oh, I see that I got 90% fake news but have no idea which ones I got wrong.
You can tell by the results “real news detection” and “fake news detection”, they don’t tell you which one is wrong, probably to avoid other people “copying” the correct answers.