Register in kotlin

 Xml :-

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    tools:context=".MainActivity">

  <LinearLayout
      android:orientation="vertical"
      android:layout_width="match_parent"
      android:layout_height="match_parent">
      <EditText
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="Email"
          android:id="@+id/registeremail"/>
      <EditText
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="Name"
          android:id="@+id/name"/>
      <EditText
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="Last Name"
          android:id="@+id/lastname"/>
      <EditText
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="Password"
          android:id="@+id/password"/>

      <Button
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="center"
          android:hint="Register"
          android:id="@+id/registerbutton"/>

  </LinearLayout>
</ScrollView>

Kotlin:-

package com.example.schooladmin

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.EditText
import android.widget.Toast
import com.example.schooladmin.databinding.ActivityMainBinding
import com.example.schooladmin.databinding.ActivityRegisterBinding
import com.example.schooladmin.ui.home.model.User
import com.google.android.gms.tasks.OnCompleteListener
import com.google.firebase.auth.FirebaseAuth
import com.google.firebase.database.DatabaseReference
import com.google.firebase.database.FirebaseDatabase

class Register : AppCompatActivity() {
    val mAuth = FirebaseAuth.getInstance()
    lateinit var mDatabase : DatabaseReference
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_register)
        val registerBtn = findViewById<View>(R.id.registerbutton)


        mDatabase = FirebaseDatabase.getInstance().getReference("Names")


        registerBtn.setOnClickListener(View.OnClickListener {
                view -> registerUser()
        })

    }

    private fun registerUser () {
        val emailTxt = findViewById<View>(R.id.registeremail) as EditText
        val passwordTxt = findViewById<View>(R.id.password) as EditText
        val nameTxt = findViewById<View>(R.id.name) as EditText
        val lastname = findViewById<View>(R.id.lastname) as EditText

        var email = emailTxt.text.toString()
        var password = passwordTxt.text.toString()
        var name = nameTxt.text.toString()
        var lastn = lastname.text.toString()

        if (!email.isEmpty() && !password.isEmpty() && !name.isEmpty()) {
            mAuth.createUserWithEmailAndPassword(email, password).addOnCompleteListener(this, OnCompleteListener { task ->
                if (task.isSuccessful) {
                    val user = mAuth.currentUser
                    val uid = user!!.uid

                    mDatabase.child(uid).child("Name").setValue(name,lastn)

                    Toast.makeText(this, "Successfully registered :)", Toast.LENGTH_LONG).show()
                }else {
                    Toast.makeText(this, "Error registering, try again later :(", Toast.LENGTH_LONG).show()
                }
            })
        }else {
            Toast.makeText(this,"Please fill up the Credentials :|", Toast.LENGTH_LONG).show()
        }
    }
}