When updating my WooCommerce product variation stock via the WooCommerce REST API url:
https://url.com/wp-json/wc/v3/products/2982/variations/2989

And posting:

{
    "stock_quantity": 145
}

It works fine and updates the stock level to 145. The value before updating it was 25. How can I receive this value in my action beneath:

add_action( 'woocommerce_rest_insert_product_variation_object', 'capture_previous_stock_quantity', 10, 3 );
function capture_previous_stock_quantity($variation, $request, $creating) {
    $current_stock_qty = $variation->get_stock_quantity();
    $headers[] = 'From: MyMail <[email protected]>';
    $mailSubject = 'Test mail API';
    $mailContent .= '<p>The current stock quantity is: '.$current_stock_qty.'</p>';
    wp_mail( '[email protected]', $mailSubject, $mailContent, $headers );
}

This returns the value 145 inside $current_stock_qty. I want the old stock level.

In the first try I had it in the action woocommerce_update_product but there the value was already updated so I thought I could get the value correct inside the action mentioned above.

But it didn’t work out. Someone knowing how to help me?