"What is the connection between lightning and electricity?"
Translation:Apa hubungan petir dengan listrik?
Due to the context of the sentence, di antara is redundant so you don't need it. Instead, to say the same thing (that is, the equivalent meaning) in Indonesian. You just say, "what connection is lighting with electricity?"
It's admittedly unhelpful that the app doesn't tell you about that structure until afterwards!