magento 2 how to get children product sku or children product id using parent product id or sku

Question

how to get children product SKU or children product id using parent product id or SKU I have these details for particular options, here are 2 arrays and I need particular product id or sku

 Array
    (
        [0] => Array
            (
                [value_index] => 5438
                [label] => Black
                [product_super_attribute_id] => 531
                [default_label] => Black
                [store_label] => Black
                [use_default_value] => 1
            )
    
        [1] => Array
            (
                [value_index] => 5907
                [label] => Silver
                [product_super_attribute_id] => 531
                [default_label] => Silver
                [store_label] => Silver
                [use_default_value] => 1
            )
    
    )

Note: I am using AMP so can not use Jquery

Answer 1

Try following code.

$configurableProduct = $objectManager->create('Magento\Catalog\Model\Product')->load($product_id);
     
    $_children = $configurableProduct->getTypeInstance()->getUsedProducts($configurableProduct);
    foreach ($_children as $child){
        echo $child->getID();
    }

NOTE: According to magento standard, do not allowed the use of Object Manager method, so implement the code by magento way.