Where and how to enable logging

In the instructions for installing Helper Libraries for Javascript at Installation — openHAB Helper Libraries documentation , Step 2 says " Use the Karaf logging commands to enable debug logging for automation: log:set DEBUG org.openhab.core.automation."

I am using the OH3 Main UI via my browser. Exactly where and how do I log:set DEBUG org.openhab.core.automation ?

Thanks.

You would enter those commands using SSH

see The karaf console - connecting via ssh

You will quickly find you need to update the libraries, the original repo has not been updated to support OH3.