Adding custom fields to products page

productsPageFunctions.php

<?php
function woo_add_custom_general_fields() {

  global $woocommerce, $post;
  
  echo '<div class="options_group">';
  
  // Number Field
    woocommerce_wp_text_input( 
        array( 
            'id'                => '_number_field', 
            'label'             => __( 'My Number Field', 'woocommerce' ), 
            'placeholder'       => '', 
            'description'       => __( 'Enter the custom value here.', 'woocommerce' ),
            'type'              => 'number', 
            'custom_attributes' => array(
                    'step' 	=> 'any',
                    'min'	=> '0'
                ) 
        )
    );
    
    // Textarea
    woocommerce_wp_textarea_input( 
        array( 
            'id'          => '_textarea', 
            'label'       => __( 'My Textarea', 'woocommerce' ), 
            'placeholder' => '', 
            'description' => __( 'Enter the custom value here.', 'woocommerce' ) 
        )
    );

    // Select
    woocommerce_wp_select( 
    array( 
        'id'      => '_select', 
        'label'   => __( 'My Select Field', 'woocommerce' ), 
        'options' => array(
            'one'   => __( 'Option 1', 'woocommerce' ),
            'two'   => __( 'Option 2', 'woocommerce' ),
            'three' => __( 'Option 3', 'woocommerce' )
            )
        )
    );
    
    // Checkbox
    woocommerce_wp_checkbox( 
    array( 
        'id'            => '_checkbox', 
        'wrapper_class' => 'show_if_simple', 
        'label'         => __('My Checkbox Field', 'woocommerce' ), 
        'description'   => __( 'Check me!', 'woocommerce' ) 
        )
    );

    // Hidden field
    woocommerce_wp_hidden_input(
    array( 
        'id'    => '_hidden_field', 
        'value' => 'hidden_value'
        )
    );
  
  echo '</div>';
	
}