LinkedIssues: How can i Access the label of the LinkedIssues Source?

[Frkn Grk]

I need to make an if condition, where i look if the sources label contains ("Conception").

I cant access it though.

WITH _format(issue) = """ Wird im ${issue.fixversion} [${issue.key}|${issue.url}]  ${issue.fixversions} r""":


if is_empty(issuelinks 
.FILTER($.type = 'Implements' AND $.destination = this)
.MAP(_format($.source))) //&& sources.label.contains("Conception"): 

issuelinks
.FILTER($.type = 'Implements' AND $.destination = this)
.MAP(_format($.source))

How can i write the underlined text correct and get it in the if condition?