Enabling 2-factor authentication is adding an extra layer of security ensuring no one, even if knowing your password, can access it.
Mobile Wallet
1 - Tap 
on the right bottom
2 - Tap Settings
3 - Tap Security
4 - Tap Enable 2-factor authentication
5 - Scan the QR code with your Authenticator App or use the Security Key generated.
6 - Insert the new Verification Code to confirm the 2-factor authentication activation.
New Web Wallet
1 - At the left, click 
to access the More options
2 - Click Security
4 - Click Enable 2-factor authentication
5 - Scan the QR code with your Authenticator App or use the Security Key generated.
6 - Insert the new Verification Code to confirm the 2-factor authentication activation.