Due to some changes in the website (we think about new anti-bot protections) login with E-Mail/Password could cause "Incorrect password" error, even when the credentials are correct.

Then to avoid this problem a new login method has been added, the Authentication key.

The Authentication key is a file created by a software (or script). This software will open the web browser in your computer, and will ask you to login in to Netflix web page.

After the login in the web page, the software will create the Authentication key file, and provide you of a PIN.
With this file+PIN (the password will be still required) you can login on any device (or system) where you have installed Kodi with Netflix add-on and so bypass the problem of "Incorrect password" error.

You can create the NFAuthentication.key file from any Personal Computer with Linux (e.g. Ubuntu), Mac or Windows (desktop / laptop). You cannot execute it on Kodi OS's (e.g. LibreELEC) or gaming console.

To create this file and get the PIN, you need to use one of the following software:

After generating the file you can use it to login to Netflix add-on on all your devices.

All the Software, Script and source code available on GitHub are provided "as is" without warranty of any kind, either express or implied. Use at your own risk. The use of the software is done at your own discretion and risk with the agreement that you will be solely responsible for any damage resulting from such activities and you are solely responsible for adequate data protection.

For details read here: https://github.com/CastagnaIT/plugin.video.netflix/issues/917