在Woocommerce单变量产品中的变体选择器下添加短代码

I would like to add a shortcode under variation selector and above add to cart button so it would open up a size chart, just like here:

I got the shortcode, but I don't know what code to use to make it appear in that specific area.

Try the following (before the selected variation price):

add_action( 'woocommerce_before_single_variation', 'add_shortcode_before_single_variation', 20 );
function add_shortcode_before_single_variation(){
    global $product;

    // HERE comes your shortcode
    echo do_shortcode( "[my_shortcode attr='blabla']" );
}

OR this one instead (after the selected variation price):

add_action( 'woocommerce_single_variation', 'add_shortcode_before_single_variation', 15 );
function add_shortcode_before_single_variation(){
    global $product;

    // HERE comes your shortcode
    echo do_shortcode( "[my_shortcode attr='blabla']" );
}

Code goes in function.php file of your active child theme (or theme).

it should work (replacing my fake shortcode with yours)…