Modify Read More link based on category being viewed

I have a category for videos on my site and I’d like the “Read More” link on those posts to say “View Now.”

I’ve tried changing the link code in content.php to the following but it doesn’t work. It doesn’t break, but it’s not changing text. Is there a better way to go about this?

 <?php if ( in_category('18') ){
                echo '<a href="';
               the_permalink();
                echo ' " class="more">';
                _e('View Now','klasik');
            echo '</a>';
            } else {
             echo '<a href="';
               the_permalink();
                echo ' " class="more">';
                _e('Read More','klasik');
            echo '</a>';
        } 
        ?>