Bought the Loyalist Version.

I bought the Loyalist Version about a year ago, does that give me the Ashes expansion, or do I have to buy it separate now?

If you bought the Loyalist edition from the GD web site, then yes.

Login to your Humble account, click the Keys link at the top middle of the page below the Humble banner. Scroll down and look for the various Grim Dawn keys. It should be there.

Here’s the link to the page, you can login from there.