Subtitle – You may also like

First of all, thank you, you did not forget this topic (https://wordpress.org/support/topic/font-display-swap-6/).
Secondly, please tell me what to add in Customizer (Custom CSS) to change H3 to H6 (line 24 „<h3><?php echo esc_html( $attributes[‘title’] ); ?></h3>” in videos-template-classic.php). The subtitle (You may also like) is too BIG compared to the others on my site. And sometimes I forget to make the change after releasing a new version.
Thanks, in advance.