Problem with project in projectsLeadByUser()

[Ben]

Hi,

I would like to use the function projectsLeadByUser(). The documentation for the function (https://support.atlassian.com/jira-software-cloud/docs/advanced-search-reference-jql-functions/#Advancedsearchingfunctionsreference-projectsLeadByUserprojectsLeadByUser--) states when using the username:
"Find open issues in projects that are led by Bill:
project in projectsLeadByUser(bill)"

If I want to use the function, I can NOT enter the username there. I have to enter another "format" of the username (e.g., "61128892627b56006871a15b"). So I can NOT enter a username in the place of "bill" in the example above.

My users want to use this feature, but do not know this different format of their or other usernames. Can anyone help me how to use the "normal" username (e.g. "Bill Bobsen") in the function instead of the other format?

Kind regards,

Ben