How to make labels available for cronjob

Hi folks

I created a backoffice-wizard doing some things for a lot of products. Last step is showing the result of the work. The displayed texts are coming from ...label.properties files

In order to avoid timeout-problems, I transferred the last step to a cronjob. But unfortunately within the cronjob-environment, the available labels are quite different. Very strange: Obviously only labels from ext-content/productcockpit/web/webroot/WEB-INF/i3-label.properties are available.

Question: How to make my labels available to cronjob?

Thanks in advance, Heiko