WebP conversion seems not working

[IlyaShkurenko]

<figure :key="src">
    <picture>
      <source :data-srcset="${src}?webp" type="image/webp"  v-if="src">
      <img :data-src="`${src}`"
           :title="title"
           :width="width"
           :height="height"
           class="lazyload"
           src="/img/loading-img.png">
    </picture>
  </figure>
using lazysizes lib for lasy load with vueJS and seems it's not converting to webP because 
webp: {
        quality: 10
 }
option doesn't affect. Maybe it's working only if images are in static folder because mine are external? Also didn't find some changes in sizes loaded content or performance

[gekkedev]

As I ran into the same issue, it seems to be related to the way Vue loads images. Image optimization must be possible at build time, because if done on-the-fly during run time it wouldn't have a good impact on performance at all. A workaround is described here.