Follow these steps to set up Touch ID:
Make sure that your finger is clean and dry.
Choose Apple menu > System Preferences.
Click Touch ID.
Click the plus sign to add a fingerprint, then type your user account password when prompted. Follow the onscreen instructions that follow.
Use the checkboxes to select the Touch ID features that you want to use on your Mac.
Tips for adding fingerprints:
Place your finger on the Touch ID button — but don’t press. Hold it there until you're asked to lift your finger.
Lift and rest your finger slowly, making small adjustments to the position of your finger each time.
You can also delete fingerprints:
Hover the pointer over a fingerprint. A delete button appears.
Click the delete button, then enter your password to remove the fingerprint.
Use Touch ID to unlock your Mac
After you set up Touch ID, you can use it to unlock your Mac. Wake up your Mac by opening the lid, pressing a key, or tapping the trackpad. Then place your finger lightly on Touch ID to log in.
You must type your password to log in after you start up, restart, or log out of your Mac. When you're logged in, you can quickly authenticate with Touch ID whenever you're asked for your password.
You can also use Touch ID to unlock these features on your Mac:
Password-protected Notes
The Passwords section in Safari preferences
System Preferences
If you have FileVault turned on, you must type your password to unlock the Security & Privacy pane and the Users & Groups pane.
If multiple users set up Touch ID and log in to the same Mac, they can use Touch ID to switch accounts. Just press Touch ID, and your Mac switches to the logged-in user account associated with the fingerprint.