How to get map from Firestore?

I want to implement a friendsystem.
Currently I am adding friends like this:

    public func addFriends(emailUser:String, emailFriend:String, completion: @escaping (Bool) -> Void) {
        
    let db = Firestore.firestore()
        
        if emailFriend == "" {
            print ("Failed to add friend")
            
            completion(false)
        }else {
    
        getUserData(email: emailFriend, isForFriend: true) { success in
            if success {
                
                db.collection("users").document(emailUser).setData([
                    "friends" : [[self.userDataOfMyFriends!.email]:[self.userDataOfMyFriends!.uid]]
                ], merge: true)
                
                completion(true)
            }else{
                print ("Failed to add friend")
                completion(false)
            }
        }
        }
    }

The Firebase data structure of the user looks like this:

email
 - "my@email.com"

friends
- 0
  - "myfriends@email.com": "AbCdeF1234567" // email:UID
uid
 - "AbCdeF1234567" //current users UID

And I am loading the profile data including friends of the current user like this:

  public func getUserData(email:String, isForFriend:Bool, completion: @escaping (Bool) -> Void) {
        let db = Firestore.firestore()
        let docRef = db.collection("users").document(email)
        print (email)
        
        docRef.getDocument { (document, error) in
            if let document = document, document.exists {
                let userEmail = document.get("email") as? String
                let userUID = document.get("uid") as? String
                let userFriends = document.get("friends") as? [[String:String]] // Here might be the problem
                if isForFriend {
                    
                self.userDataOfMyFriends = UserData(email: userEmail, uid: userUID, friends: userFriends)
                } else {
                self.userData = UserData(email: userEmail, uid: userUID, friends: userFriends)
                }
                print("userdata geladen")
                print (self.userData)
                completion(true)
            
                
            } else {
                
                
                completion(false)
            }
        }
    }

My UserDataModel looks like this:

public struct UserData {
    var email:String?
    var uid:String?
    var friends:[[String:String]]?

}

But the result is always nil.
How do I get the "map" data from Firebase in my UserDataModel?

>Solution :

So you need

let userFriends = document.get("friends") as? [String:String]

As friends is a dictionary not an array , hence

var friends:[String:String]?