Latest Fire OS 8 user agents:

User Agent Browser Device
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/548.1.0.51.64;IABMV/1;] Facebook 548 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 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/551.1.0.58.63;IABMV/1;] Facebook 551 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 [FB_IAB/FB4A;FBAV/546.0.0.42.66;IABMV/1;] Facebook 546 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.7559.228 Safari/537.36 Chrome 144 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/551.1.0.58.63;IABMV/1;] Facebook 551 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 Instagram 419.0.0.49.71 Android (30/11; 240dpi; 1200x1920; Amazon; KFTUWI; tungsten; mt8169; en_US; 896334196; IABMV/1) Instagram 419 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.7559.228 Safari/537.36 Chrome 144 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/551.1.0.58.63;IABMV/1;] Facebook 551 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 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/551.1.0.58.63;IABMV/1;] Facebook 551 Fire HD 10 (2023)
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 Safari/537.36 [FB_IAB/FB4A;FBAV/551.1.0.58.63;IABMV/1;] Facebook 551 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 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/551.1.0.58.63;IABMV/1;] Facebook 551 Fire HD 8 (2022)
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36 Mozilla/5.0 (Linux; Android 11; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/98.4.4 like Chrome/98.0.4758.136 Safari/537.36 Mobile Silk 98 Fire HD 8 (2022)
Mozilla/5.0 (Linux; U; Android 11; en-; KFQUWI Build/RS8327.2526N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.6478.186 Mobile Safari/537.36 PHX/15.3 Phoenix Browser 15 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; Tablet; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/130.5.9 like Chrome/130.0.6723.142 Safari/537.36 Mobile Silk 130 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/130.3.3 like Chrome/130.0.6723.102 Safari/537.36 Mobile Silk 130 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/128.2.1 like Chrome/128.0.6613.146 Safari/537.36 [ip:94.134.177.91] Mobile Silk 128 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/128.2.1 like Chrome/128.0.6613.146 Safari/537.36 [ip:94.134.177.85] Mobile Silk 128 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/128.2.1 like Chrome/128.0.6613.146 Safari/537.36 [ip:94.134.177.80] Mobile Silk 128 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/128.2.1 like Chrome/128.0.6613.146 Safari/537.36 [ip:94.134.177.69] Mobile Silk 128 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/128.2.1 like Chrome/128.0.6613.146 Safari/537.36 Mobile Silk 128 Fire HD 10 (2023)