They ask you JS basics and give some codes like make a todo or async programming , event loops ,fetch ,promises. etc, Then if you face any difficulties you can ask for seeing the docs also , It's not very difficult , you can do it fine.

3 rounds in total. 1st written test of coding with easy to meduim level questions . Round 2 technical interview in which 2-3 medium level dsa questions were asked . Final demo round of teaching of any topic you want.