[Vue warn]: Failed to resolve component: router-view - vue.js

Question

I'm a newbie to Vue.js and first time dealing with vue-router.
Just created a few files and for some reason I don't get to see the template. Compiled successfully but in the browser I get the following error: Failed to resolve component: router-view
main.js
import { createApp } from 'vue';
import VueRouter from 'vue-router';
import { store } from './store';
import App from './App.vue';
import AuthHandler from './components/AuthHandler';
const router = new VueRouter({
mode: 'history',
routes: [
{ path: '/oauth2/callback', component: AuthHandler }
]
});
const app = createApp(App)
app.use(router)
app.use(store)
app.mount('#app')
App.vue
<template>
<div>
<AppHeader></AppHeader>
<router-view></router-view>
</div>
</template>
<script>
import AppHeader from "./components/AppHeader";
export default {
name: "App",
components: {
AppHeader
}
};
</script>
components/AuthHandler.vue
<template>
<div>
... Please wait
</div>
</template>
<script>
export default {
name: "AuthHandler"
};
</script>
Here is the package.json
package.json
{
"name": "images",
"version": "0.1.0",
"private": true,
"scripts": {
"serve": "vue-cli-service serve",
"build": "vue-cli-service build",
"lint": "vue-cli-service lint"
},
"dependencies": {
"axios": "^0.21.1",
"core-js": "^3.6.5",
"lodash": "^4.17.21",
"qs": "^6.10.1",
"vue": "^3.0.0",
"vue-router": "^3.5.2",
"vuex": "^4.0.2"
},
"devDependencies": {
"#vue/cli-plugin-babel": "~4.5.0",
"#vue/cli-plugin-eslint": "~4.5.0",
"#vue/cli-service": "~4.5.0",
"#vue/compiler-sfc": "^3.0.0",
"babel-eslint": "^10.1.0",
"eslint": "^6.7.2",
"eslint-plugin-vue": "^7.0.0"
},
"eslintConfig": {
"root": true,
"env": {
"node": true
},
"extends": [
"plugin:vue/vue3-essential",
"eslint:recommended"
],
"parserOptions": {
"parser": "babel-eslint"
},
"rules": {}
},
"browserslist": [
"> 1%",
"last 2 versions",
"not dead"
]
}

Answer 1

I resolved the problem in the following way. I believe the issue relay on the vue/vue-router versions. I hope this is the correct way :-)
main.js
import { createApp } from 'vue';
import App from './App.vue';
// import VueRouter from './vue-router';
import { createWebHistory, createRouter } from "vue-router";
import { store } from './store';
import AuthHandler from './components/AuthHandler';
const router = createRouter({
history: createWebHistory(),
routes: [
{ path: '/about', component: AuthHandler }
]
});
const app = createApp(App)
app.use(router)
app.use(store)
app.mount('#app')

Answer 2

I was an idiot, I wanted to use 'vue add vue-router'. Of course it didn't work.
Vue add router
is the command.
npm install vue-router#4
only installs the package, won't add it to the app. If all is well, main.js should look like this:
import App from "./App.vue";
import router from "./router";
createApp(App).use(router).mount("#app");
Unfortunately they forgot to add it to the documentation...