Programmatically add WP pages or posts

AddWPPages.php

<?php
//Create Page
function create_page() {
  if ( !$post = get_page_by_path( 'product-configurator', OBJECT, 'post_type' ) ) {
    $user_id = get_current_user_id();
  
    $page = array(
        'post_title' => 'Product Configurator',
        'post_status' => 'publish',
        'post_author' => $user_id,
        'post_type' => 'page',
    );

    $page_exists = get_page_by_title( $page['post_title'] );

    if( $page_exists == null ) {
      // Page doesn't exist, so lets add it
      $insert = wp_insert_post( $page );
      if( $insert ) {
        // Page was inserted ($insert = new page's ID)
      }
    }
  }
}
add_action( 'wp_loaded', 'create_page' );