[Vuejs]-No loader is configured for .vue files: error on nuxt 3 project

The problem is the package itself. If you go to /node_modules/vue3-simple-html2pdf/src/index.js you will see this line:

import Vue3SimpleHtml2pdf from 'vue3-simple-html2pdf/src/vue3-simple-html2pdf'

add a .vue to the end.

import Vue3SimpleHtml2pdf from 'vue3-simple-html2pdf/src/vue3-simple-html2pdf.vue'

This is problematic though (if you update or download it onto a different device…). You should ask the package creator to do it.