Find Default Product Variation from WooCommerce

functions.php

function find_matching_product_variation( $product ) { 
    $is_default_variation = false;

    $default_attributes = $product->get_default_attributes();
    foreach($product->get_available_variations() as $variation_values ){
        foreach($variation_values['attributes'] as $key => $attribute_value ){
            $attribute_name = str_replace( 'attribute_', '', $key );
            $default_value = $product->get_variation_default_attribute($attribute_name);
            if( $default_value == $attribute_value ){
                $is_default_variation = true;
            } else {
                $is_default_variation = false;
                break; // Stop this loop to start next main lopp
            }
        }
        if( $is_default_variation ){
            $variation_id = $variation_values['variation_id'];
            break; // Stop the main loop
        }
    }

    return $is_default_variation;
}