Shan Ye

It’s where the number plate lights are

Sounds like a dodgy stalk switch. Maybe get a second hand one on ebay and try it?

How old is the battery? I'd start there, by checking if the battery good enough and check all the battery connections and the earth.

The passenger door of my 2016 Twingo 3 isn't in line with the rear door. I suspect the striker plate needs adjusting to pull it in a...