Never download APKs from suspicious URLs like "netflix-hack-free-4k.apk" – these are often ransomware for Android TV.
To get Netflix working, you must typically "sideload" a specific version. Depending on your device's certification, you have two main options:
These are standard Netflix apps ripped from smartphones. They work on TV boxes but require a mouse or air-mouse for navigation because the interface is not remote-friendly. Versions like netflix-8.1.2-build-38416.apk may run smoothly but still at 480p.