We cover this in our docs here:
By default, we will apply f_auto to image delivered by Cloudinary through the Wordpress integration, meaning automatic format. Among the formats that f_auto can deliver is WebP, but WebP is sometimes not the optimal format for the user's operating system and browser combination. (Avif and Jpeg 2000 being the other two common optimized file format types.
If you would like to change the default transformation option from f_auto to f_webp, that can be done from the image transformation settings, as shown in the linked doc above.
Please let me know if that was not clear, or if there is anything else I can help answer!
Thank you for explaining this, I was hoping that once we do our site speed tests we don't get the notice "Serve images in next-gen formats" Not sure if having the jpg extension will impact this property.
Thank you for the update. Speed test application will pick up the mime type when it receives the image from Cloudinary and should appropriately detect it as webp format regardless of the extension name.
Let us know if there are any other issues.