How to prevent default, then submit default with VueJS - vue.js

Question

I am submitting a form using VueJS and i need to submit two actions on the final submit, one after the other.
Either one works when running just one.
What i am trying to do, is signup a user for firebase, wait, then submit the form with the same email/password as normal and signup that user with another sign in system.
The delimiters have been changed, so just over look that.
How to do this with Jquery
<form #submit="checkForm" #submit.prevent="register" action="#" method="post" novalidate="true" ref="form">
<h1 class="text-center">{{ 'customer.register.title' | t }}</h1>
<h1 v-if="authUser">
Is authed in
</h1>
<h1 v-else>
Not auth
</h1>
<div class="form-group">
<ul>
<li v-for="error in errors">
${ error }
</li>
</ul>
</div>
<p>
<label for="CustomerFirstName">${ firstName }</label>
<input id="name" v-model="name" type="name" name="customer[first_name]" autocomplete="name"
autocorrect="off" autocapitalize="off">
</p>
<p>
<label for="CustomerEmail">${ loginEmailName }</label>
<input id="email" v-model="email" type="email" name="customer[email]" autocomplete="email"
autocorrect="off" autocapitalize="off">
</p>
<p>
<label for="CustomerPassword">${ loginPasswordName }</label>
<input id="password" v-model="password" type="password" name="customer[password]">
</p>
<p>
<button type="submit" value="Create" class="btn btn-primary">Submit</button>
</p>
</form>
Then the JS that works on either one but not together.
const appTwo = new Vue({
delimiters: ["${", "}"],
el: "#create_customer_vue",
data: {
errors: ["1", "2", "3"],
email: '',
password: '',
name: null,
firstName: "First name",
loginEmailName: emailTitle,
loginPasswordName: passwordTitle,
title: registerTitle,
authUser: null
},
methods: {
register: function() {
firebase.auth().createUserWithEmailAndPassword(this.email, this.password)
},
submitForm: function(){
this.$refs.form.submit()
},
created() {
firebase.auth().onAuthStateChanged(user => { this.authUser = user })
},
checkForm: function(e) {
if (this.email && this.password) {
return true;
}
this.errors = [];
if (!this.email) {
this.errors.push("Valid email required");
}
if (!this.password) {
this.errors.push("Valid password required");
}
e.preventDefault();
}
}
});

Answer 1

Just call the one submit handler then submit the form normally after the Firebase operation completes.
For example
<form #submit.prevent="register" ... >
methods: {
checkForm () {
if (this.email && this.password) {
return true;
}
this.errors = [];
if (!this.email) {
this.errors.push("Valid email required");
}
if (!this.password) {
this.errors.push("Valid password required");
}
return false
},
async register ($event) {
if (this.checkForm()) {
await firebase.auth().createUserWithEmailAndPassword(this.email, this.password)
$event.target.submit() // or use this.$refs.form.submit() if you prefer
}
}
}