Add this function to the plugin that is highly sought after by many

Hide message (You cannot add another “PRODUCT NAME” to your cart) Product Page.
`add_filter( ‘woocommerce_add_to_cart_validation’, ‘one_cart_item_at_the_time’, 10, 3 );
function one_cart_item_at_the_time( $passed, $product_id, $quantity ) {
if( ! WC()->cart->is_empty())
WC()->cart->empty_cart();
return $passed;
}