WooCommerce: Check the number of different cart items / SKUs in cart
You can use the following, that will get the count of different product(s) sku(s) in cart:
<?php $skus = array();foreach( WC()->cart->get_cart() as $cart_item ) : $sku = $cart_item['data']->get_sku(); $skus[$sku] = $cart_item['data']->get_id();endforeach; if( count($skus) > 1 ) : woocommerce_button_proceed_to_checkout();endif; ?>It should work.