What region's dialect is this?

I am watching a video of Jonathan and Patricia with Korean subtitles. I want to improve my reading and listening skills through this, but various dialects are used in the video, and I would like to understand the background better. For example, there is a part where Jonathan says, "문을 빨리 안 여냐잉." Here, "여냐잉" seems to be an expression derived from '열다,' but I am not sure what additional meaning this ending carries. Since I am at a beginner to intermediate level, I haven't learned many different endings yet. Could you provide advice on what dialect this expression is from and if there are any rules associated with it? Any additional insights would be greatly appreciated.