Missing tool to convert to webp in batch queue manager

Hey, i have a verry simple question but i could’t find an answer in the digikam documentation or faqs nor over google.
I want to export multiple files to the webp format using the batch queue manager. Now the Tool to convert to webp format is missing even though in the queue settings / saving images there are settings possible for webp.

thanks for any hint
digikam version 8.1.0