You get a Netflix activation code when you use a device such as a gaming console or tablet to sign into Netflix. Some devices provide an activation code that links to your Netflix account.
Go to Netflix.com/activate on a computer or laptop, sign in to your account, and enter the code to activate the device and link it to your Netflix account. Both the device and your computer must be connected to the Internet for activation to work. Some devices that may provide you with an activation code are Xbox, Playstation and Nintendo gaming consoles, as well as Roku boxes and tablets.