Librem Key with Heads on X230

Hi all, I have flashed Heads onto my x230 and have had it working nicely with TOTP. I recently bought a Librem Key to take it one step further and use it for HOTP verification (with the LED). However, I cannot seem to find a way to make HOTP verification available. I have looked everywhere and just cannot find instructions for doing that. Would greatly appreciate it if someone could point me in the right direction.