Latest Fire OS 7 user agents:

User Agent Browser Device
Mozilla/5.0 (Linux; Android 9; AFTBOXE1 Build/PS7711.5272N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Mobile Safari/537.36 Chrome Webview 138 65UF3D63DA
Mozilla/5.0 (Linux; Android 9; KFMAWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/547.0.0.41.68;IABMV/1;] Facebook 547 Fire HD 10 (2019)
Mozilla/5.0 (Linux; Android 9; KFMAWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/534.0.0.56.76;IABMV/1;] Facebook 534 Fire HD 10 (2019)
Mozilla/5.0 (Linux; Android 9; KFKAWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/494.0.0.55.73;] Facebook 494 Fire HD 8 (2018)
Mozilla/5.0 (Linux; Android 9; KFONWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/510.0.0.72.41;IABMV/1;] Facebook 510 Fire HD 8 (2020)
Mozilla/5.0 (Linux; Android 9; KFMAWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/464.0.0.60.90;] Facebook 464 Fire HD 10 (2019)
Mozilla/5.0 (Linux; Android 9; KFKAWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/552.0.0.44.65;] Facebook 552 Fire HD 8 (2018)
Mozilla/5.0 (Linux; Android 9; KFMAWI Build/PS7331.4463N) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 10 (2019)
Mozilla/5.0 (Linux; Android 9; KFTRWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/548.1.0.51.64;IABMV/1;] Facebook 548 Fire HD 10 (2021)
Mozilla/5.0 (Linux; Android 9; AFTTIFF43 Build/PS7712.5370N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Mobile Safari/537.36 Chrome Webview 138 Fire TV Omni QLED (2022)
Mozilla/5.0 (Linux; Android 9; KFTRPWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 10 Plus (2021)
Mozilla/5.0 (Linux; Android 9; KFMUWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire 7" (2019)
Mozilla/5.0 (Linux; Android 9; KFTRWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.224 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 10 (2021)
Mozilla/5.0 (Linux; Android 9; KFMUWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/549.0.0.61.62;IABMV/1;] Facebook 549 Fire 7" (2019)
Mozilla/5.0 (Linux; Android 9; KFTRPWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 Instagram 420.0.0.55.74 Android (28/9; 240dpi; 1200x1920; Amazon; KFTRPWI; trona; mt8183; en_US; 903616219; IABMV/1) Instagram 420 Fire HD 10 Plus (2021)
Mozilla/5.0 (Linux; Android 9; AFTHA004 Build/PS7712.5370N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Mobile Safari/537.36 Chrome Webview 138 Fire TV 4K (2022)
Mozilla/5.0 (Linux; Android 9; KFONWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/443.0.0.23.229;] Facebook 443 Fire HD 8 (2020)
Mozilla/5.0 (Linux; Android 9; KFKAWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 8 (2018)
Mozilla/5.0 (Linux; Android 9; KFONWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 [FB_IAB/FB4A;FBAV/552.1.0.45.68;IABMV/1;] Facebook 552 Fire HD 8 (2020)
Mozilla/5.0 (Linux; Android 9; KFTRWI Build/PS7331.4463N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/138.0.7204.244 Safari/537.36 Instagram 420.0.0.55.74 Android (28/9; 240dpi; 1200x1920; Amazon; KFTRWI; trona; mt8183; en_US; 903616219; IABMV/1) Instagram 420 Fire HD 10 (2021)