Latest Amazon Fire TV 4-Series (2023) user agents:

User Agent	Browser	Platform
Mozilla/5.0 (Linux; Android 9; AFTKAUK001) AppleWebKit/537.36 (KHTML, like Gecko) Silk/120.2.3 like Chrome/120.0.6099.232 Safari/537.36	Mobile Silk 120	Fire OS 7
Mozilla/5.0 (Linux; Android 9; AFTKAUK001 Build/PS7681.4384N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/124.0.6367.248 Mobile Safari/537.36/8.5.0 (Linux;Android 9) ExoPlayerLib/2.6.1	Chrome Webview 124	Fire OS 7
Mozilla/5.0 (Linux; Android 9; AFTKAUK001) AppleWebKit/537.36 (KHTML, like Gecko) Silk/130.5.7 like Chrome/130.0.6723.142 Safari/537.36	Mobile Silk 130	Fire OS 7