CURL7.76.0 curl: unknown --write-out variable: 'errormsg'

CURL version: 7.76.0.
OS: MacOS

The documentaition says:

-w, --write-out <format>

errormsg The error message. (Added in 7.75.0)
exitcode The numerical exitcode of the transfer. (Added in 7.75.0)
onerror The rest of the output is only shown if the transfer returned a non-zero error (Added in 7.75.0)

But using them inside Terminal:

curl -s -w "%{errormsg}\n%{exitcode}\n%{onerror}\n" "https://api.github.com/users/lambda" >> log.txt

I am getting:

curl: unknown --write-out variable: 'errormsg'
curl: unknown --write-out variable: 'exitcode'
curl: unknown --write-out variable: 'onerror'

Could somebody please shed some light?