Latest Fire OS user agents:

User Agent Browser Device
Mozilla/5.0 (Linux; Android 11; KFRAPWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.7680.199 Safari/537.36 Chrome 146 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFSNWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/146.3.7 like Chrome/146.0.7680.199 Safari/537.36 Mobile Silk 146 Fire Max 11
Mozilla/5.0 (Linux; Android 11; KFRAPWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/146.3.7 like Chrome/146.0.7680.199 Safari/537.36 Mobile Silk 146 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFQUWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.7680.199 Safari/537.36 Chrome 146 Fire 7 (2022)
Hulu/1.180.0 (Fire OS 8.1.6.6 (RS8166/3481); ; AFTHY7ABBA; Build/Neutron - 1.4.596) Hulu 1 Unknown
Mozilla/5.0 (Linux; Andr0id 11; AFTSH3F7EF-T6C-Freely-6FA-2CC-001) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.7727.20 Safari/537.36 OMI/4.27.0.97.AFTdev.1088 HbbTV/1.7.1 (+DRM;Amazon;AFTSH3F7EF-T6C-Freely-6FA-2CC-001;0032112404356;unknown;com.amazon.MT9026;) FVC/9.0 (Amazon;com.amazon.MT9026;) smarttv_AFTSH3F7EF-T6C-Freely-6FA-2CC-001_Build_0032112404356_Chromium_147.0.7727.20 Opera Devices 4 Unknown
Hulu/1.178.0 (Fire OS 8.1.5.7 (RS8157/3603); ; AFTHY7ABBA; Build/Neutron - 1.4.596) Hulu 1 Unknown
Mozilla/5.0 (Linux; Android 11; KFRAWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/146.3.7 like Chrome/146.0.7680.199 Safari/537.36 Mobile Silk 146 Fire HD 8 (2022)
Mozilla/5.0 (Linux; Android 11; KFTUWI) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.7680.199 Safari/537.36 Chrome 146 Fire HD 10 (2023)
Hulu/1.178.0 (Fire OS 8.1.6.6 (RS8166/3482); ; AFTKRT; Build/Neutron - 1.4.596) Hulu 1 Fire TV Stick 4K Max (2023)