Persistent Cookie Help Required!

[bits2017]

This is a login.php.

The user is given a choice to either input his/her Username & Password or Email & Password. In short, either log-in inputting your Username or your Email.

It is written in mysqli procedural. I have not learned pdo oop yet. I need help in the login.php to add the "Remember Me" feature using Cookies. I have googled but most tutorials teach to save the user password in the cookie! And that is a big NO! NO!
Therefore, I do not trust these tutorials any more. But, I trust the php folks here!
Can someone be the Great Samaritan here to show me an example code of how the cookie part should be coded in php ? You're welcome to not start from scratch but work on my work (login.php).
registration.php, logout.php and account_acivation.php finished. Those last 3 files are working fine. Working on the home.php now.


login.php

    <?php
 
    /*
    ERROR HANDLING
    */
    declare(strict_types=1);
    ini_set('display_errors', '1');
    ini_set('display_startup_errors', '1');
    error_reporting(E_ALL);
    mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
 
    include 'config.php';
 
    // check if user is already logged in
    if (is_logged() === true) 
    {
        //Redirect user to homepage page after 5 seconds.
        header("refresh:2;url=home.php");
        exit; //
    }
 
 
    if (isset($_POST["login_username_or_email"]) && 
    isset($_POST["login_password"]))
        {
            $username_or_email = trim($_POST["login_username_or_email"]);
            $password = $_POST["login_password"];        
 
            //Select Username or Email to check against Mysql DB if they are 
            already registered or not.
 
            if(strpos("$username_or_email", "@"))
            {
                $email = $username_or_email;
 
                $query = "SELECT ids, usernames, passwords, emails, 
                accounts_activations_statuses FROM users WHERE emails = ?";
                $stmt = mysqli_stmt_init($conn);
                $stmt = mysqli_prepare($conn, $query);            
                mysqli_stmt_bind_param($stmt, 's', $email);
                mysqli_stmt_execute($stmt);
                //$result = mysqli_stmt_get_result($stmt); //Which line to use ? 
                This line or the next ?
                $result = mysqli_stmt_bind_result($stmt, $db_id, $db_username, 
                $db_password, $db_email, $db_account_activation_status); // 
                Which line to use ? This line or the one above ?
            }
            else
            {
                $username = $username_or_email;
 
                $query = "SELECT ids, usernames, passwords, emails, 
                accounts_activations_statuses FROM users WHERE usernames = ?";
                $stmt = mysqli_stmt_init($conn);
                $stmt = mysqli_prepare($conn, $query);
                mysqli_stmt_bind_param($stmt, 's', $username);
                mysqli_stmt_execute($stmt);
                $result = mysqli_stmt_bind_result($stmt, $db_id, $db_username, 
                $db_password, $db_email, $db_account_activation_status); // 
                Which line to use ? This line or the one above ?
            }
 
            $row = mysqli_stmt_fetch($stmt);        
            mysqli_stmt_close($stmt);
 
            if (!password_verify($password, $db_password))
            {
                echo "Incorrect User Credentials!';<br>";
                exit();
            }
            else
            {
                $_SESSION["user"] = $db_username;            
                header("location:home.php?user=$db_username");    
            }
        }    
    ?>