Arabic is spoken in many countries but every region has a different dialect, does anyone know which dialect is taught in this course?
It's not a dialect. It's Modern Standard Arabic, MSA, the lingua franca that everyone knows, at least knows how to write in.
Modern Standard Arabic, here's an article that pretty much explains all: https://making.duolingo.com/what-makes-arabic-hard-and-why-that-shouldnt-stop-you-from-learning-it
Everyone understands MSA. And people practice their religion in MSA. They write in MSA. They study in MSA.
Honestly, based on knowledge of Arabic, I would say there is little bit of Egyptian and Levantine dialect, but mostly Modern Standard Arabic.