LayerSlider Updates

How do I go about getting updates for LayerSlider that came with the Oblivion theme?

((You have version 5.6.9. The latest version is 6.0.5.))

The purchase key that came with the theme doesn’t work, and the message associated with the update alert reads:

((Set up auto-updates to upgrade to this new version, or request it from the author of your theme if you’ve received LayerSlider from them.))

Please advise