SwiftUI Edit User Account using data from Firestore - ios

Question

I'm very new to SwiftUI and I'm trying to create a very basic login/logout system in SwiftUI on IOS with the ability to edit the users profile. I have two main functions in the signup process, function register and function AddInfo which then actually adds the user to the db.
both in AuthenticationView.swift
func register(){
if self.email != ""{
if self.pass == self.repass{
//Creating the user
Auth.auth().createUser(withEmail: self.email, password: self.pass) { (res, err) in
if err != nil{
self.error = err!.localizedDescription
self.alert.toggle()
return
}
//Add user info to database
AddInfo(username: self.username, email: self.email)
print("success")
UserDefaults.standard.set(true, forKey: "status")
NotificationCenter.default.post(name: NSNotification.Name("status"), object: nil)
}
}
else{
self.error = "Password mismatch"
self.alert.toggle()
}
}
else{
self.error = "Please fill all the contents properly"
self.alert.toggle()
}
}
Then i have an addinfo function which adds the user to a database. The document ID of the db is the users UID and then it creates a username, email and uid automatically and i've made it create a blank entry for Firstname and Lastname.
func AddInfo(username: String, email: String) {
let db = Firestore.firestore()
let user = Auth.auth().currentUser
if let user = user {
// The user's ID, unique to the Firebase project.
// Do NOT use this value to authenticate with your backend server,
// if you have one. Use getTokenWithCompletion:completion: instead.
let uid = user.uid
//let email = user.email
//let photoURL = user.photoURL
db.collection("users").document(uid).setData([
"UID": uid,
"Username": username,
"Email": email,
"First Name": "",
"Last Name": ""])
}
This is what the DB looks like when a user registers
database look when user registers
So with all of this in mine, i'm struggling with creating a Edit user profile view. How would I go about doing this? All i need is a page that shows the users registered email, username and then they can add their first and last name (first and last name isn't included on the registration form, that's something i'd like to add after they've registered)
I've tried reading the Firestore view my profile document but i'm struggling to get my head around it