Latest Fire OS user agents:

User Agent Browser Device
Mozilla/5.0 (Linux; Android 11; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.4.3 like Chrome/148.0.7778.265 Safari/537.36 Mobile Silk 148 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFQUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.3.5 like Chrome/148.0.7778.258 Safari/537.36 Mobile Silk 148 Fire 7 (2022)
Mozilla/5.0 (Linux; Android 11; KFSNWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.7778.258 Safari/537.36 Chrome 148 Fire Max 11
Mozilla/5.0 (Linux; Android 11; AFTKRT) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.3.5 like Chrome/148.0.7778.258 Safari/537.36 Mobile Silk 148 Fire TV Stick 4K Max (2023)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.3.5 like Chrome/148.0.7778.258 Safari/537.36 Mobile Silk 148 Fire HD 10 (2023)
Mozilla/5.0 (Linux; Android 11; AFTBR92D74) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.3.5 like Chrome/148.0.7778.258 Safari/537.36 Mobile Silk 148 Unknown
Mozilla/5.0 (Linux; Android 11; KFRAPWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.3.5 like Chrome/148.0.7778.258 Safari/537.36 Mobile Silk 148 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFSNWI Build/RS8338.3339N) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/146.0.7680.219 Safari/537.36 [FB_IAB/FB4A;FBAV/565.0.0.49.74;IABMV/1;] Facebook 565 Fire Max 11
Mozilla/5.0 (Linux; Android 11; KFRAPWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.7778.258 Safari/537.36 Chrome 148 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/148.3.5 like Chrome/148.0.7778.258 Safari/537.36 Mobile Silk 148 Fire HD 8 (2022)