Start an application after Android boot

Question

I need to know how to make an application that I created in Android and made in Android Studio runs automatically when the device boots.

The only thing I have found is this guide https://codigofacilito.com/articulos/auto-ejecucion-de-una-aplicacion-al-inicio-de-un-depositivo-con-android but it does not run when the device starts.

ANDROID MANIFEST

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.resolucion.pruebaauto">
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
    <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=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

        <receiver android:enabled="true"
            android:name=".Auto"
            android:permission="android.permission.RECEIVE_BOOT_COMPLETED">

            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED"/>
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </receiver>
    </application>
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
</manifest> 

BROADCAST RECEIVER

package com.resolucion.pruebaauto;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class Auto extends BroadcastReceiver{
    public void onReceive(Context context,Intent intent) {
        if (Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) {
            Intent i = new Intent(context, MainActivity.class);
            i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(i);
        }

    }
} 

MAINACTIVITY

package com.resolucion.pruebaauto;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

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