A while back I have written the article: How To Serve Images In Next-Gen Formats Using WordPress but since then some time has past and new plugin emerged that can help do this easily and even server the images from Statically CDN.
The plugin is called Flying Images and can help you do this for free. With the help of this plugin, you can load your images compressed and in WebP format for free.
I have created a video with all the tests and configurations and in there you can also see how Fling Images is doing against ShortPixel a premium image optimization plugin that can do the same.
See the below video to see exactly the configurations and results of using the plugin and how it stands out against Shortpixel.