Snowflake broker survival guide journalctl command for logs doesn't work

I want to view the broker logs on the snowflake-broker host (post-upgrade, #40349 (closed)).

The Snowflake Broker Survival Guide currently says:

Logs are managed by systemd, access it with journalctl --user -u broker.service.

But that command doesn't work for me:

# journalctl --user -u broker.service
No journal files were found.
-- No entries --

What is the correct command to view the logs? Let's update the survival guide.