Practice Problems SERP Feature is Now Official

We saw this test early this year and it looks like it’s now official. This interactive feature tests your knowledge of high school math, chemistry and physics topics directly on Search. Start by looking up a subject matter like “chemical bond practice problems”. 

The content comes from providers like BBC Bitesize, Byjus, Careers360, Chegg, CK12, Education Quizzes, GradeUp, Great Minds, Kahoot!, OpenStax, Toppr, Vedantu and more. AFAIK there is no info on how you can apply for this and is likely invite-only.