Super late to the party but can confirm @TwistedTwigleg and @Megalomaniak are correct. If you look in the example branch, there is a project you can download and see the code to use achievements. There is also a tutorial in the documentation that (I hope) does a decent job of explaining how to implement them.
You will need to set up your achievements in the Steamworks back-end and publish them to be able to trigger them in a game. To know they are working, you will call storeStats after calling setAchievement( achieve name) and you'll see a little pop-up message saying you've unlocked the achievement.
If you need more assistance, feel free to contact me or check out our Discord.
