How to Add Filed in Single Product Page In WordPress

This code use for you can add files to your Single Product page, and this code adds your function.php file WordPress.

<?php
add_action( 'woocommerce_product_options_general_product_data', 'woocom_general_product_data_custom_field' );

function woocom_general_product_data_custom_field() {
  // Create a custom text field

  // Text Field
  woocommerce_wp_text_input(
    array(
      'id' => '_new_regular_price',
      'label' => __( 'New Regular Price', 'woocommerce' ),
      'placeholder' => 'New Regular Price',
      'desc_tip' => 'true',
      'description' => __( 'Regular Price', 'woocommerce' )
    )
  );
}
add_action( 'woocommerce_process_product_meta', 'woocom_save_general_proddata_custom_field' );

function woocom_save_general_proddata_custom_field( $post_id ) {
 $text_field = $_POST['_new_regular_price'];
 if( ! empty( $text_field ) ) {
  update_post_meta( $post_id, '_new_regular_price', esc_attr( $text_field ) );
 }
}
?>