If it’s a tech interview, practice solving coding problems in a tech interview format.

Find simple “coding challenge” problems, write the answers on paper, get satisfied with them, then run them and see what happens. Definitely at least cover the basics (reverse a linked list, quicksort). Do it until you’re comfortable with it, which takes a while. You will start to ace programming tests because the calibrated response is for someone who does programming in a totally different format, and you’re comfortable and experienced with the unusual format.