Cigaret lighter not working

I am not that familiar with peugeot's but. You can buy a test light for cheap or construct one if you have the parts. And most cars have a fuse box inside the car and another one outside under the hood.
At the least you can pull each fuse at a time and check if thier burnt out.
Also check to see if there's a foreign object (like a coin) in the cig lighter socket.