At church without the "the" should also be accepted. In English, we mostly just say church, not the church. Like, you would say, "I'm going to the store," but you would say, "I'm going to church."
I usually use "the". "I am going to pagoda" doesn't sound right. Same with "I am going to temple". But it seems a waste of time to comment as both are acceptable and it would take years before Duo responds.