Sanity serializers to convert a tag to nuxt-link (nuxt 3).

nuxt-file

//helpers/link.vue

<template>
<nuxt-link :to="href" v-if="isInternalLink"> <slot /></nuxt-link>
<a :href="href" v-else> <slot /></a>
</template>

<script setup>

const props = defineProps({
    href: String
})
const isInternalLink = computed(() => {
    return props.href.startsWith('/') ? true : false
})
</script>

//Nuxt page or Nuxt component

<template>
  <SanityContent :blocks="block1.page.body" :serializers="serializers" />
<template/>

<script setup>
import Link from '~/helpers/Link.vue'
const serializers = {
     types: {
       youtube: YouTube
    },
    marks: { link: Link },
}
</script>