When I save document as image file, only support one page at a time?

When I save document as webp with writer, it saves only a page to webp or png. I want to save all page as each image file. How to do it? Or it is not possibel now?

https://superuser.com/questions/1741308/how-to-export-all-libreoffice-writer-pages-in-one-go-as-images