Latest Fire OS 8 user agents:

User Agent Browser Device
Mozilla/5.0 (Linux; Android 11; KFQUWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.7559.246 Safari/537.36 Chrome 144 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.7559.246 Safari/537.36 Chrome 144 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; AFTMA08C15 Build/RS8166.3482N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Mobile Safari/537.36 Chrome Webview 142 Unknown
Mozilla/5.0 (Linux; Android 11; KFTUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI Build/RS8338.3339N) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/543.0.0.55.73;IABMV/1;] Facebook 543 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI Build/RS8333.2734N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/124.0.6367.248 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;] Facebook 552 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFQUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; KFTUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 Instagram 420.0.0.55.74 Android (30/11; 240dpi; 1200x1920; Amazon; KFTUWI; tungsten; mt8169; en_US; 903616219; IABMV/1) Instagram 420 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFQUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; KFRASWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Unknown
Mozilla/5.0 (Linux; Android 11; KFRAPWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/530.0.0.48.74;IABMV/1;] Facebook 530 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFRAPWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Andr0id 11; AFTSH3F7EF-Freely-1AE-2CC-002) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.7559.110 Safari/537.36 OMI/4.27.0.9.AFTdev.1054 HbbTV/1.7.1 (+DRM;Amazon;AFTSH3F7EF-Freely-1AE-2CC-002;0031508515718;unknown;com.amazon.MT9026;) FVC/9.0 (Amazon;com.amazon.MT9026;) smarttv_AFTSH3F7EF-Freely-1AE-2CC-002_Build_0031508515718_Chromium_144.0.7559.110 Opera Devices 4 Unknown
Mozilla/5.0 (Linux; Android 11; KFSNWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/540.0.0.49.148;IABMV/1;] Facebook 540 Fire Max 11
Mozilla/5.0 (Linux; Android 11; KFQUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/542.0.0.46.151;IABMV/1;] Facebook 542 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; KFSNWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/537.0.0.47.77;IABMV/1;] Facebook 537 Fire Max 11
Mozilla/5.0 (Linux; Android 11; KFTUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFSNWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire Max 11
Mozilla/5.0 (Linux; Android 11; KFRAPWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Safari/537.36 Instagram 420.0.0.55.74 Android (30/11; 213dpi; 800x1280; Amazon; KFRAPWI; raspite; mt8169; en_US; 903616219; IABMV/1) Instagram 420 Fire HD 8 (2022)