According to the unofficial Kodi site, https://seo-michael.co.uk/, Amazon are making it difficult to use Kodi on the fire stick. Wont allow it on their Home page but it will always work somehow I'm sure.
I can see an opportunity here. Buy loads of Fire sticks and pre-programme them with Kodi. Then put them inside another box with an HDMI cable and resell them for £99
Any one want to invest or even buy one from me?