Which method's of hashing the password is better and safer in PHP Codeigniter?

Question

Hi i just started learning codeigniter, through tutorials on youtube. I've learned a different hashing method with each tutorial, and I wonder which of the methods are better and safer. I have read people's different opinions about md5(), that it's safe by proper use, and that it's not safe because it's very fast. So should I only use the hashing method from exaple 1? Or are there even better easy methods to hash the password? I'm a dummy so please expand your answer as much as posible.

Exaple 1 using:

$options = ['cost' => 12];

$encripted_pass = password_hash($this->input->post('password'), PASSWORD_BCRYPT, $options);

public function create_user(){

    $options = ['cost' => 12];

    $encripted_pass = password_hash($this->input->post('password'), PASSWORD_BCRYPT, $options);

    $data = array(
        'first_name' => $this->input->post('first_name'),
        'last_name' => $this->input->post('last_name'),
        'email' => $this->input->post('email'),
        'username' => $this->input->post('username'),
        'password' => $encripted_pass         
    );

    $inser_data = $this->db->insert('users', $data);
    return $inser_data;
}

public function login_user($username, $password){
    
    $this->db->where('username', $username);        

    $result = $this->db->get('users');

    $db_password = $result->row(6)->password;

    if(password_verify($password, $db_password)){
        return $result->row(0)->id;
    }else{
        return false;
    }

}

Or:

Example 2 using md5() function in:

Function register() -> $enc_password = md5($this->input->post('password'));*

and

Function login() -> $password = md5($this->input->post('password'));

// Register user
    public function register(){
        $data['title'] = 'Sign Up';
        
        $this->form_validation->set_rules('name', 'Name', 'required');
        $this->form_validation->set_rules('username', 'Username', 'required|callback_check_username_exists');
        $this->form_validation->set_rules('email', 'Email', 'required|callback_check_email_exists');
        $this->form_validation->set_rules('password', 'Password', 'required');
        $this->form_validation->set_rules('password2', 'Confirm Password', 'matches[password]');

        if($this->form_validation->run() === FALSE){
            $this->load->view('templates/header');
            $this->load->view('users/register', $data);
            $this->load->view('templates/footer');
        } else {
            // Encrypt password
            $enc_password = md5($this->input->post('password'));

            $this->user_model->register($enc_password);

            // Set message
            $this->session->set_flashdata('user_registered', 'You are now registered and can log in');

            redirect('posts');
        }
    }

    // Log in user
    public function login(){
        $data['title'] = 'Sign In';
    
        $this->form_validation->set_rules('username', 'Username', 'required');
        $this->form_validation->set_rules('password', 'Password', 'required');

        if($this->form_validation->run() === FALSE){
            $this->load->view('templates/header');
            $this->load->view('users/login', $data);
            $this->load->view('templates/footer');
        } else {
            // Get username
            $username = $this->input->post('username');
            // Get and encrypt the password
            $password = md5($this->input->post('password'));
            // Login user
            $user_id = $this->user_model->login($username, $password);                

            if($user_id){
                // Create session
                $user_data = array(
                    'user_id' => $user_id,
                    'username' => $username,
                    'logged_in' => true
                );

                $this->session->set_userdata($user_data);

                // Set message
                $this->session->set_flashdata('user_loggedin', 'You are now logged in');

                redirect('posts');
            }else{
                // Set message
                $this->session->set_flashdata('login_failed', 'Login is invalid');

                redirect('users/login');
            }                
        }
    }