In https://www.problogger.gr/blog/ how can modify theme to remove Excerpt and read more button from all posts in /blog. I want to show ONLY post title. I’ve tried this

p.more-link {
display: none !important;
}

and this:

function modify_read_more_link() {
return ”;
}
add_filter( ‘the_content_more_link’, ‘modify_read_more_link’ );

without success.