Update not available
Theme Update notifications and 1-click updating can only happen if your license key is activated (active). You will want to check to ensure you have your license key added to your theme and also, make sure you added a website to your key by logging into your account here at Rough Pixels.
To activate your license key, go to Appearance > Theme License
Add your key into the license key field and click the Save Changes button:

Getting an unauthorized message
When you activate your license, the URL you’re activating it from is authorized by Rough Pixels.
If that URL changes at any time, you need to re-authorize your license key or you’ll receive an “unauthorized” error when trying to update.
To re-authorize your license key, go to Appearance > Theme License and make sure the correct license key is in the field. Then click the Save Changes button under your license key field.