Hi @ramesh-r!
This theme has multiple templates, which means, that this codepart can be found in multiple files, and based on some settings, different ones are loading on the different pages/posts. Like I can find the banner in the page.php file, and in these files as well:
template-blog.php
template-full.php
template-home.php
template-left-sidebar.php
template-three-column.php
\content\home-page-small.php
In this case all of them have the same code to make that banner:
<?php if ( has_post_thumbnail() ) { ?>
<div class="feature-img page-banner" <?php if ( ! empty( $thumb ) ) { ?> style="background-image: url(<?php echo esc_url( $thumb[0] ); ?>);" <?php } ?>>
<h1 class="headline img-headline"><?php the_title(); ?></h1>
<?php the_post_thumbnail( 'giving-featured-large' ); ?>
</div>
<?php } ?>
what you should remove, and just write our code there with your slider’s ID:
<?php
echo do_shortcode('[smartslider3 slider=15]');
?>
But for example at my posts another code is used there, which is inside the header.php file, and it is a longer code, so I’ll tell the beginning and the end. It starts from line 158. for me:
<!-- BEGIN #header -->
and ends at line 212., so one line under the “END #header”:
<!-- END #header -->
</div>
You could remove that whole part, and write our shortcode there:
<?php
echo do_shortcode('[smartslider3 slider=15]');
?>
Rather have a backup of the files, in case you need to modify them differently, as you do on first try.
