I was working on application design in Photoshop and here we need a webp file. How do I save or export from Photoshop as webp?
Photoshop doesn't have it added to its program on the go. That meaning you'll have to download a plugin in order to export to webp formats.
You can find the plugin for Photoshop here: https://developers.google.com/speed/webp/docs/webpshop
As soon as this is installed you should be able to save/export to the extension.
You can find free plugins for Photoshop here (select the appropriate platform):