create registration form

					<?php
/**
 * Plugin Name: WP Plugin Example
 * Description: Example plugin for creating a registration form.
 * Version: 1.0
 * Author: Your Name
 * Author URI: https://your-website.com
 * Text Domain: wpturbo
 */

// Register the shortcode for the registration form
add_shortcode( 'registration_form', 'wpturbo_registration_form_shortcode' );

/**
 * Shortcode callback function for the registration form
 */
function wpturbo_registration_form_shortcode() {
    ob_start();

    // Check if the user is already logged in
    if ( is_user_logged_in() ) {
        echo '<p>You are already registered and logged in.</p>';
    } else {
        ?>
        <form id="registration-form" method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>">
            <input type="hidden" name="action" value="wpturbo_process_registration">
            
            <!-- Add your registration form fields here -->
            <p>
                <label for="username">Username:</label>
                <input type="text" name="username" id="username" required>
            </p>
            
            <p>
                <label for="email">Email:</label>
                <input type="email" name="email" id="email" required>
            </p>
            
            <p>
                <label for="password">Password:</label>
                <input type="password" name="password" id="password" required>
            </p>
            
            <p>
                <input type="submit" value="Register">
            </p>
        </form>
        <?php
    }

    return ob_get_clean();
}

/**
 * Process the registration form data
 */
add_action( 'admin_post_wpturbo_process_registration', 'wpturbo_process_registration' );
add_action( 'admin_post_nopriv_wpturbo_process_registration', 'wpturbo_process_registration' );
function wpturbo_process_registration() {
    // Verify the nonce
    if ( ! isset( $_POST['_wpnonce'] ) || ! wp_verify_nonce( $_POST['_wpnonce'], 'wpturbo_registration_nonce' ) ) {
        wp_die( 'Invalid nonce' );
    }

    // Get the submitted form data
    $username = sanitize_text_field( $_POST['username'] );
    $email    = sanitize_email( $_POST['email'] );
    $password = $_POST['password'];

    // Create the new user
    $user_id = wp_create_user( $username, $password, $email );

    // Check if user creation was successful
    if ( is_wp_error( $user_id ) ) {
        // User creation failed, display an error message
        wp_die( $user_id->get_error_message() );
    } else {
        // User creation successful, log the user in
        wp_set_auth_cookie( $user_id );
        wp_redirect( home_url() ); // Redirect to the home page
        exit;
    }
}