DTG today is the full version key. Before key works you have to have downloaded free DTG from Amazon App Store. If it came through another source, download the DTG free version and it will replace the non Amazon DTG app. Then you can download and install today's free key.
Thanks so much for the info. I was able to get the free app but now showing two DTG icons. One for main and another showing a key. Can I delete the main ?
Also, if you look carefully you will see that the key is only applicable for the special Amazon Market Free Version of the full app. You need both parts, and you can't just reuse the key.