I use in WordPress the plugin WebP Express. In my WordPress theme, the plugin works quite well, and I can use the images in webp-format. To achieve this, I simply append the extension .webp to the URL of the images.
Now I would like to delete all jpeg images in my WordPress environment to save disk space.
Is there an elegant way that WordPress appends the extension webp to all URLs that access images? In my theme, I have solved this via programming. But how could I solve this, for example, in the admin interface or even in plugin's? I do not want to change the WordPress core files.