Chivalry 2 Game Keys

Go to https://www.epicgames.com/ and click 'Get Epic Games' (in the upper right corner of the site) to download the launcher,
Install the launcher, create a new Epic Games account or login into an existing one,
In the Epic Games launcher, click on your profile name in the bottom left corner of the client, and choose 'Redeem Code',
Enter the code and click 'Redeem'.