Questions are to be loaded from Open Trivia Database API when connected to internet and from given JSON file if not connected to internet.
this is an easy work if you how to use Web.Get. In the Web.URL, You can join different parameters for levels/types/categories.
I have made an extension for Open Trivia DB, check out.
I have not tested in app inventor but i will test it and will release in app inventor community as well.
GetToken function is missed, maybe you want to add it in new release.