Trying to display name of users on support action bar - database

Question

Please i am new to kotlin and i have been trying to retrive the fullname of my users in the data base after using getStringExtra so i can use each of them for the title of my support action bar but the value it returns an empty value.
val name = intent.getStringExtra("fullname")
val receiverUid = intent.getStringExtra("uid")
val senderUid = FirebaseAuth.getInstance().currentUser?.uid
mDbRef = FirebaseDatabase.getInstance().getReference()
senderRoom = receiverUid + senderUid
receiverRoom = senderUid + receiverUid
supportActionBar?.title = name
Here is how i am sending name and receiverUid to my database
sendButton.setOnClickListener{
val message = messageBox.text.toString()
val messageObject = Message(message, senderUid)
val name = name.toString()
val receiverUid = receiverUid.toString()
val chatlistObject = ModelChatList(name, message, receiverUid)
mDbRef.child("chats").child(senderRoom!!).child("messages").push()
.setValue(messageObject).addOnSuccessListener {
mDbRef.child("chats").child(receiverRoom!!).child("messages").push()
.setValue(messageObject).addOnSuccessListener {
mDbRef.child("Chatlist").push().setValue(chatlistObject)
}
}
messageBox.setText("")
But when i try to retrive my ModelChatlist object it returns only two values leaving out the receivername as shown in the ModelChatlist below
class ModelChatList {
private var receivername:String = ""
private var lastmessage:String = ""
private var uid:String = ""
constructor(){}
constructor(receivername: String, lastmessage:String, uid:String){
this.receivername = receivername
this.lastmessage = lastmessage
this.uid =uid
}
fun getReceivername(): String{
return receivername
}
fun setReceivername(receivername: String){
this.receivername= receivername
}
fun getUid(): String{
return uid
}
fun setUid(uid: String){
this.uid= uid
}
fun getLastmessage(): String{
return lastmessage
}
fun setLastmessage(lastmessage: String){
this.lastmessage= lastmessage
}
}
In case you are wondering, "fullname" is in my database as the name the users enter when they sign up. Thank You