VueJS add external site to router history - vue.js

Question

I am building an app using Vue Router that uses an "external" site for login credentials. It essentially looks like this:
Home.Vue
<template>
</template>
<script>
export default {
name: "Home",
data() {
return {
}
},
created() {
window.location = 'https://third_party_site.com?nextpage=http://my_site.com/#/entry'
}
}
</script>
<style scoped>
</style>
This third_party_site.com handles auth and sends a JWT back as a query string in the resulting URL. When I try to use a navigation guard (as shown below) to get the query string, Vue router only looks in the router's history.
router/index.js
import Vue from 'vue'
import Router from 'vue-router'
import Home from '#/components/Home'
import Entry from '#/components/Entry'
Vue.use(Router)
export default new Router({
routes: [
{
path: '/',
name: 'Home',
component: Home,
},
{
path: '/entry',
name: 'Entry',
component: Entry,
beforeEnter: (to, from, next) => {
console.log('to',to)
console.log('from',from)
console.log('next',next)
next()
},
meta: {
title: 'Entry'
}
},
]
})
The console prints the expected "to" location but the "from" location is the base path, "/", and there are no query parameters. How do I go about getting the "external" route so I can access the query parameters? The resulting console.log of "from" is below.
from
{name: null, meta: {…}, path: "/", hash: "", query: {…}, …}
fullPath: "/"
hash: ""
matched: []
meta: {}
name: null
params: {}
path: "/"
query: {}
__proto__: Object
Before asking, the app, in its current state, has to be built this way and I do not have access to the external site.

Answer 1

Wild shot in the dark here but the # in your nextpage query parameter is probably messing with the remote site.
What it will see is
QUERY => nextpage=http://my_site.com/
FRAGMENT => #/entry
so it will redirect back to http://my_site.com/ because it probably ignores any fragment.
You should encode the value correctly, eg
window.location = 'https://third_party_site.com/?nextpage=' +
encodeURIComponent('http://my_site.com/#/entry')
which will produce nextpage=http%3A%2F%2Fmy_site.com%2F%23%2Fentry