EXTENSION parameter in Redshift UNLOAD function not working

Hi, I am trying to use EXTENSION parameter in Redshift UNLOAD function to save file in .csv extension in S3 bucket. However, I am getting the error: "ERROR: syntax error at or near "EXTENSION" . As per AWS documentation (https://docs.aws.amazon.com/redshift/latest/mgmt/cluster-versions.html#cluster-version-173), EXTENSION parameter has been added in 1.0.45698 version (Released on January 20, 2023). The version of my redshift cluster is up to date and is 1.0.46523 and therefore does not seem to be the version issue.