Make your WhatsApp account secure by enable Two-Step Verification passcode from WhatsApp settings on iPhone or Cellular iPad. https://www.howtoisolve.com/enable-whatsapp-tow-step-verification-iphone/
https://www.howtoisolve.com/disable-tow-step-verification-whatsapp/
Six Digit passcode or password for authentication purpose, So no one can use or setup whatsApp account on another device.
Reset forgotten or lost whatsApp password (2-SV passcode).
https://www.howtoisolve.com/reset-forgot-whatsapp-2-step-verification-passcode/
WhatsApp users can try this security features on iPhone Xs Max, iPhone XS, iPhone XR, iPhone X, iPhone 8 Plus, iphone 8, iPhone 7, 7 Plus, iPhone 6, 6 Plus, iPhone 6S, iPhone 6S Plus, iPhone SE and other compatible models.
Enable/ Disable WhatsApp passcode or password