use filters in v for loop [ Working Example ]

It is easy not that hard have a look

<li class="nav-item" v-for="post in posts"  :key="post.id">
  <router-link :to="`/post/${post.category_name}`|lowerCase">
      {post.category_name|lowerCase}
  </router-link>
</li>

In code above we are using filter lowerCase on Post Category Variable.

Filter looks like this

lowerCase(value){
    return value.toLowerCase();
}

So this out puts all category names in lower case. Hope it helps