/*Directly go to add to cart */
function redirect_to_cart() {
   return wc_get_cart_url();
}
add_filter( 'woocommerce_add_to_cart_redirect', 'redirect_to_cart' );
add_filter( 'wc_add_to_cart_message_html', '__return_false' );


------------Use the following to add the link of add to cart---------------


/?add-to-cart=id
or

www.yourwebsite.com/?add-to-cart=id