Latest Fire OS 8 user agents:

User Agent Browser Device
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/554.0.0.57.70;IABMV/1;] Facebook 554 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/554.0.0.57.70;IABMV/1;] Facebook 554 Fire Max 11
Hulu/1.177.1 (Fire OS 8.1.6.0 (RS8160/3380); ; AFTKM; Build/Neutron - 1.4.559) Hulu 1 Fire TV Stick 4K (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 Mobile Safari/537.36 [Pinterest/Android] Pinterest Fire HD 10 (2023)
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/554.0.0.57.70;IABMV/1;] Facebook 554 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFRAWI 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/553.0.0.56.58;IABMV/1;] Facebook 553 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFQUWI Build/RS8338.3339N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.224 Safari/537.36 [Pinterest/Android] Pinterest 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/553.0.0.56.58;IABMV/1;] Facebook 553 Fire Max 11
Mozilla/5.0 (Linux; Andr0id 11; AFTHAD9E7D) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.7632.110 Safari/537.36 OMI/4.27.0.39.AFTdev.1071 HbbTV/1.5.1 (+DRM;Amazon;AFTHAD9E7D-Panasonic-TV-0;0031576018054;unknown;com.amazon.SoC=MT9026;) FVC/5.0 (Amazon;com.amazon.SoC=MT9026;) smarttv_AFTHAD9E7D-Panasonic-TV-0_Build_0031576018054_Chromium_145.0.7632.110 Opera Devices 4 Unknown
Mozilla/5.0 (Linux; Android 11; KFQUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/144.5.4 like Chrome/144.0.7559.246 Safari/537.36 Mobile Silk 144 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/144.2.2 like Chrome/144.0.7559.177 Safari/537.36 Mobile Silk 144 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/146.1.90 like Chrome/146.0.7680.153 Safari/537.36 Mobile Silk 146 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFRASWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.7559.246 Safari/537.36 Chrome 144 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/553.0.0.56.58;IABMV/1;] Facebook 553 Fire HD 8 (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 [FB_IAB/FB4A;FBAV/553.0.0.56.58;IABMV/1;] Facebook 553 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/553.0.0.56.58;IABMV/1;] Facebook 553 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; AFTDEC012E Build/RS8166.3481N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Mobile Safari/537.36 Chrome Webview 142 4K Fire TV (2024)
Mozilla/5.0 (Linux; Android 11; AFTHU71990 Build/RS8157.3603N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/140.0.7339.201 Mobile Safari/537.36 Chrome Webview 140 Unknown
Mozilla/5.0 (Linux; Android 11; KFRAPWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.7339.251 Safari/537.36 Chrome 140 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; AFTNE4E43F Build/RS8166.3481N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/142.0.7444.236 Mobile Safari/537.36 Chrome Webview 142 Unknown