P: Camera Raw/Lightroom Classic/Lightroom Ecosystem: Support for WebP

For Windows, that should probably work fine, since you can run command-line utilities as Export post-processing actions. However, on Mac, I think you'd need to use the Run Any Command plugin to invoke the conversion utility, since you can't directly use a command-line program as an Export post-processing action on Mac.

There's a free Google conversion tool at the bottom of this page which might work as a LR post action. If for some reason you didn't want to use PS to do it. https://developers.google.com/speed/webp/

LR doesn't support WebP directly.  To export to WebP, you'll have to export as TIFF or JPEG and then convert using a third-party converter.  You could likely create a Photoshop droplet that uses the Photoshop WebP plugin to convert, and then install the droplet as a post-process action in a LR Export preset, so that you could export directly to WebP.