Electro - Product id in single product description meta

functions.php

add_action( 'woocommerce_product_meta_start', 'add_product_id_to_single_meta' );
function add_product_id_to_single_meta() {
	global $product;

	if ( ! $product ) {
		return;
	}

	echo '<span class="product-id">Product ID: ' . esc_html( $product->get_id() ) . '</span>';
}