In this case you need override:
wp-content/plugins/haru-formota-core/templates/recent-new/carousel.php (or other file if you choose other style at settings).
You can add this code to display readmore button:
Please follow step to step on topic How to customize use child theme (you should use file manger of your hosting or use FTP to create or copy from plugin template folder to override). Because you custom work will lost if you do it direct in parent theme. Please patient and follow tutorial (already have screenshot)