KL does not fly to AGP, but they codeshare ex CDG with AF and ex-MAD/BCN with UX (Air Europa).
In both cases, your itinerary must start/end in AMS or beyond to have a KL-code on the CDG/MAD-AGP segment.
ex UK, it probably makes more sense to fly the whole way with AF (via CDG)at GBP159+tax ex NCL.
Alternatively, ex-LGW, UX has a fare at GBP108+tax (via MAD or PMI)