Event Manager Action Command fails to execute

[sim4life]

I installed SFTPgo using docker image v2 (and postgresql) and managed to setup a WebDAV endpoint. Using WebAdmin, I created a new user and using WebClient for that user, I added a few files to my WebDAV storage. Now I want to be able to take a backup for my WebDAV added files from the container path location and save in a tar ball.
I figured out that I can create an Event Manager Action Command with a tar command like:
Name: tst-compress
Command: /usr/bin/tar
Arguments: --zstd,-cf,"$BKUP_DIR/bkup-$(date '+%Y-%m-%d').tar.zst",-C,{{VirtualDirPath}},.
Environment Variables: BKUP_DIR: /srv/sftpgo/backups/{{VirtualDirPath}}

where {{VirtualDirPath}} placeholder is expected to be the username of the WebDAV storage -- same as WebClient username.
to be able to execute this command:
tar --zstd -cf "/srv/sftpgo/backups/username/bkup-$(date '+%Y-%m-%d').tar.zst" -C /username .

-C /username is supposed to be a relative path with the full path being: /srv/sftpgo/data/username

In my docker-compose.yml, I also added another environment variable for my container:
SFTPGO_COMMON__EVENT_MANAGER__ENABLED_COMMANDS: "/usr/bin/tar"

Event Manager Rule Schedule
Name: Compress backup

However, I am getting an error when executing the Event Manager Rule Schedule (I turned on debugging to a file):

{"level":"debug","time":"2024-11-18T20:00:00.007","sender":"eventmanager","message":"executing scheduled rule \"Compress backup\""}
{"level":"debug","time":"2024-11-18T20:00:00.034","sender":"eventmanager","message":"executed command \"/usr/bin/tar\", elapsed: 13.088265ms, error: exit status 2"}
{"level":"error","time":"2024-11-18T20:00:00.034","sender":"eventmanager","message":"unable to execute action \"tst-compress\" for rule \"Compress backup\", elapsed 13.55974ms, err: action \"tst-compress\" failed: exit status 2"}
{"level":"debug","time":"2024-11-18T20:00:00.034","sender":"eventmanager","message":"execution for scheduled rule \"Compress backup\" finished"}

Tar command has an exit status 2
Is there a problem with the placeholder {{VirtualDirPath}}?
Is it possible to log the full command that is being executed on the sftpgo.log file (with placeholders and env vars expanded)?