app crashes on activity call of library module from app module

Question

I am having an issue during calling activity of android library module from app module; however, it's crashing over and over again.

I researched all around the google without luck. Could you please help me to resolve this issue as soon as possible because I have to submit my university project?

I have created just 3 modules: Two Modules are Donor & Admin Modules and the 3rd Application Library module that contains welcome screen. I want to call activity from donor and admin module to library module but it's getting crashed.

Please check what I am doing wrong. Thanks.

Admin Module Java Code

package com.plasmadonor.admin;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import com.plasmadonor.pdapplication.Login;

public class AdminSignUpActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_sign_up);


    }

    public void btn_signin(View view) {
        Toast.makeText(this, "Button Clicked", Toast.LENGTH_SHORT).show();
        Intent i = (new Intent(this, Login.class));
        startActivity(i);

    }
}

Dependencies are already added in build.gradle

   implementation project(':PDApplication')   

Run Error

D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
   Process: com.plasmadonor.admin, PID: 21360
   java.lang.RuntimeException: Unable to start activity ComponentInfo{com.plasmadonor.admin/com.plasmadonor.pdapplication.Login}: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.plasmadonor.admin. Make sure to call FirebaseApp.initializeApp(Context) first.
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
       at android.app.ActivityThread.-wrap11(Unknown Source:0)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
       at android.os.Handler.dispatchMessage(Handler.java:105)
       at android.os.Looper.loop(Looper.java:164)
       at android.app.ActivityThread.main(ActivityThread.java:6541)
       at java.lang.reflect.Method.invoke(Native Method)
       at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
    Caused by: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.plasmadonor.admin. Make sure to call FirebaseApp.initializeApp(Context) first.
       at com.google.firebase.FirebaseApp.getInstance(com.google.firebase:firebase-common@@16.0.2:240)
       at com.google.firebase.auth.FirebaseAuth.getInstance(Unknown Source:1)
       at com.plasmadonor.pdapplication.Login.onCreate(Login.java:54)
       at android.app.Activity.performCreate(Activity.java:6975)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892) 
       at android.app.ActivityThread.-wrap11(Unknown Source:0) 
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593) 
       at android.os.Handler.dispatchMessage(Handler.java:105) 
       at android.os.Looper.loop(Looper.java:164) 
       at android.app.ActivityThread.main(ActivityThread.java:6541) 
       at java.lang.reflect.Method.invoke(Native Method) 
       at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) 

AndroidManifest.xml Code

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.plasmadonor.admin">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".AdminSignUpActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>