Images don’t convert to .webp

Hello,

I tried your plugin on my test environment. I used the option to convert all images that where already uploaded to the website AND I also uploaded new images.
I did not see any of the images turn into a .webp.

Should the plugin turn the images to a .webp format? The images on my website are already compressed by an image compressor tool. Also one of the images I uploaded. Is that the reason you tool does turn it into a webp?
I also uploaded an image of 1,2MB, but that is not possible with wordpress. So I need to compress it before uploading. But then it does not use your tool again.

So I’m curious if I should see the .webp at my images and what the best approach is with big images if I use your tool.

With kind regards,

Lianne Klaver