Using the '--encoding UTF-8' flag give error 'UTF-8 is not a supported character-encoding'

When running a command using the '--encoding UTF-8' flag, e.g.

op whoami --encoding UTF-8

I get this error:

[ERROR] 2023/02/22 08:49:05 UTF-8 is not a supported character-encoding

According to the https://developer.1password.com/docs/cli/reference#alternative-character-encoding, UTF-8 is a valid flag and the default.

1Password Version: 2.14.0
Extension Version: Not Provided
OS Version: Ubuntu 20.04.5 LTS
Browser:_ Not Provided