3 electronic keys that can be cloned for a garage (Bevendean BN2)

we had an electric opening garage door with 2 electronic keys. We bought a new one, and were able to clone it from the old keys. So now we have 2 older keys, and one newer key all fully functional. When we bought the new key it was £50....so really want these to go to someone who will use them well . Setting them up is simple -- if you have at least one of your garage electronic keys operational thank you