To set up two-step verification for WhatsApp, you need to take the following steps:
1-Open WhatsApp (duh!)
2-Go to Settings
3-Go to Account
4-Look for Two-step verification
5-Tap on Enable
6-On the next screen, enter six-digit passcode.
7-Next, re-enter six-digit passcode.
8-Optionally, add your email address on the next screen.
In the last step – optional, as mentioned – WhatsApp asks for an email address to link with your account. This email address will let WhatsApp to send a link via email to disable two-step verification in case user forgets the six-digit passcode.
Remember that in case you user forget the six-digit passcode, WhatsApp won’t permit re-verifying the account within seven days of last using WhatsApp.