2010 Twingo - only 1 key

[chopper602]

Hi,

I'm about to buy a first car for my son, 2010 Twingo (plenty of miles on it, but it's been well serviced) and everything is Ok with it apart from only having one key. It's a key rather than a card, two buttons on it (lock and unlock). Are these easy to get replacements for ? I guess there will be a transponder within the key itself . . ..

Cheers,