Instructions
2) Click Security & Privacy.
3) In the bottom left-hand corner, click the lock icon.
4) Authenticate using Touch ID.
Alternatively, you may type a username and password with administrative privileges on your Mac. Then, click Unlock.
5) Under the FileVault tab, click Enable Users.
6) To unlock the disk, you may need to enter a username and password and click Unlock.
7) Next to the user account that you wish to enable for unlocking the disk, click the Enable User button.
8) Ask the user to type their own password. After that, click OK.
9) A green circle with a check mark will appear next to their account indicating that it's been enabled. You may then click Done.
OUTCOME
The user account has been granted access to unlock the encrypted disk.