Please explain why this sentence is ok /not ok

I was doing Duolingo and it said

この部屋は二つ戸があります

My understanding right now is that the counter 二つ cannot go before the noun 戸.

Therefore

・この部屋は戸が二つあります

・この部屋は戸二つがあります

・この部屋は二つの戸があります

Would all be ok. But according to another redditer who helped me, Duo’s sentence is correct. I just don’t understand why.

I remember one of the first things I learned on that let’s learn Japanese 1980s series with ヤンさんway back was that you must say チョコレート(を)二枚ください and they hammered home you cannot use the English word order and say 二枚(を)チョコレートください.

Of course this is a completely different sentence , but I always remembered it when choosing the counters position.

Now I’m confused.

Edit: one of my 3 sentences had an error.

reddit.com
u/SuperSan93 — 1 day ago

Can you explain this mistake?

I know that counters do not lead the noun unless you add の (二つの〇〇) so what’s the reason it’s been done it here? Something unique about this word or is it a mistake?

This was a listening exercise and the voice also put the counter first.

The ‘explain my answer’ just says 二つ戸 means 2 doors.

u/SuperSan93 — 1 day ago