Download the Netflix app on that newer device to "link" it to your account history. Return to your iOS 9.3.5 device and follow the steps above. Important Note on Functionality
Some older versions struggle to connect to modern Netflix servers. netflix ipa for ios 935 link
Netflix’s servers now require newer security certificates and DRM protocols (Widevine L3/L1, FairPlay 3.0) that old app versions lack. Download the Netflix app on that newer device