Issues sending emails

The plug in, installed through WordPress, won’t send any emails. An error appears:

call_user_func_array() expects parameter 1 to be a valid callback, class ‘WC_Emails’ does not have a method ‘send_transactional_email’ in public_html/wp-includes/plugin.php on line 505

Is there a plug in piece missing?

https://www.ads-software.com/plugins/yith-woocommerce-recover-abandoned-cart/