I needed to rephrase my question since it was a bit vague before, hopefully its better now!

To start of with, I have created an account at firebase for autentification and I have also followed the step to connect the android account to the online firebase site. I have added SDK as well for the projekt. It shows that it is successfully connected to firebase!

I want to now add be able to add a user with email and password only to this database, as shown in the picture below (This is a mock up, not mine!).

I have written some code for it, as seen below for my SignInActivity and my SignUpActivity. The app compiles and runs without any issues but the users are not saved/registered in firebase website on autentification section. This sections shows blank, without any added e-mail. How can I achieve a successfull registration? If anyone needs more info/code/explanation, just request and I will provide!

SignInActivity:

package com.codingstuff.loginandsignup

import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.codingstuff.loginandsignup.databinding.ActivitySignInBinding
import com.google.firebase.auth.FirebaseAuth

class SignInActivity : AppCompatActivity() {

    private lateinit var binding: ActivitySignInBinding
    private lateinit var firebaseAuth: FirebaseAuth

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivitySignInBinding.inflate(layoutInflater)
        setContentView(binding.root)


        firebaseAuth = FirebaseAuth.getInstance()

        binding.textView.setOnClickListener {
            val intent = Intent(this, SignUpActivity::class.java)
            startActivity(intent)
        }

        binding.button.setOnClickListener {
            val email = binding.emailEt.text.toString()
            val pass = binding.passET.text.toString()

            if (email.isNotEmpty() && pass.isNotEmpty()) {

                firebaseAuth.signInWithEmailAndPassword(email, pass).addOnCompleteListener {
                    if (it.isSuccessful) {
                        val intent = Intent(this, MainActivity::class.java)
                        startActivity(intent)
                    } else {
                        Toast.makeText(this, it.exception.toString(), Toast.LENGTH_SHORT).show()

                    }
                }
            } else {
                Toast.makeText(this, "Empty Fields Are not Allowed !!", Toast.LENGTH_SHORT).show()

            }
        }
    }

SignUpActivity:

package com.codingstuff.loginandsignup

import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.codingstuff.loginandsignup.databinding.ActivitySignUpBinding
import com.google.firebase.auth.FirebaseAuth

class SignUpActivity : AppCompatActivity() {

    private lateinit var binding: ActivitySignUpBinding
    private lateinit var firebaseAuth: FirebaseAuth

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivitySignUpBinding.inflate(layoutInflater)
        setContentView(binding.root)

        firebaseAuth = FirebaseAuth.getInstance()

        binding.textView.setOnClickListener {
            val intent = Intent(this, SignInActivity::class.java)
            startActivity(intent)
        }
        binding.button.setOnClickListener {
            val email = binding.emailEt.text.toString()
            val pass = binding.passET.text.toString()
            val confirmPass = binding.confirmPassEt.text.toString()

            if (email.isNotEmpty() && pass.isNotEmpty() && confirmPass.isNotEmpty()) {
                if (pass == confirmPass) {

                    firebaseAuth.createUserWithEmailAndPassword(email, pass).addOnCompleteListener {
                        if (it.isSuccessful) {
                            val intent = Intent(this, SignInActivity::class.java)
                            startActivity(intent)
                        } else {
                            Toast.makeText(this, it.exception.toString(), Toast.LENGTH_SHORT).show()

                        }
                    }
                } else {
                    Toast.makeText(this, "Password is not matching", Toast.LENGTH_SHORT).show()
                }
            } else {
                Toast.makeText(this, "Empty Fields Are not Allowed !!", Toast.LENGTH_SHORT).show()

            }
        }
    }
}

CodePudding user response：

The problem was that I needed to manually add the SHA-1 key to the project. This was done by doing the following steps:

1. Going to gradle in the right corner, shown in step 1.
2. Press the icon in step 2.
3. Paste this or type it after the gradle: signingreport
4. Run the program/ press enter, the SHA-1 code should be shown in the console. Copy the code. Keep in mind this code should be kept private
5. Next, go to the Firebase website -> click on your project -> in the left corner where it says: Firebase Overview, click the settings icon -> Project settings.
6. Scroll down to where you see app id, app nickname, etc. Below all, you see SHA certificate fingerprints. Click on add fingerprint and paste the SHA-1 key that you copied from your android studio. Re-run your project and now when you go to the Authentification section, the e-mail should be registered!