If you want the ability to request text messages to help you access or recover your Netflix account, you can add a phone number from your Account page on the Netflix website in the Membership and Billing section under Add Phone Number.
If you have provided your phone number, and you want to update it, or you no longer wish to be able to receive text messages to help you access or recover your account, you can go to your Account page on the Netflix website under Change phone number in the Membership and Billing section and then either update or remove your phone number.
You may also opt out of text messages from Netflix and receive help by replying to the text message. Use the following messages:
STOP: Stops all messages
HELP: Redirects to the Help Center for more tips