Key blanks
I'm afraid we don't sell keys separately, and each set is unique to each lockset. If you contact a local locksmith, they may be able to help you out. Let us know what you think.
I have this same Andersen key lock on my patio doors at home, believe it or not. Personally, what I did to make this work was to use a Schlage key and have it made to match the Andersen key. However, there is a possibility you may have to file down the tip of the new key to fit into the Andersen lock. I recommend having a close look at the genuine Andersen key so that you can see that the tip of it is tapered down. I hope this helps. Make sure to get back to us and let us know how everything worked out.