Map not complete

Only got my Dreame Robot vacuum and it has mapped my house but missed 2 rooms at the end of my hall. Can they be added in or do I have to remap my entire house! Also how do I quick map the house when it’s not cleaning

Open the doors and send it to clean those rooms — it'll usually pick them up and add them on. If not, I'd factory reset and let it map the whole place again from scratch.