WordPress at a glance
function is not described

woocommerce_single_variation_add_to_cart_button() WC 1.0

Output the add to cart button for variations.

No Hooks.

Return

null. Nothing.

Usage

woocommerce_single_variation_add_to_cart_button();

Code of woocommerce_single_variation_add_to_cart_button() WC 5.3.0

<?php
function woocommerce_single_variation_add_to_cart_button() {
	wc_get_template( 'single-product/add-to-cart/variation-add-to-cart-button.php' );
}