I fix this issue little bit -- I paste below code in Search.php , Article.php , home.php and author.php . Then search on blog option is showing on top on mobile and desktop both... Can anyone tell me how to show this option only on mobile not on desktop.
<div class="blg-side-block blg-search">
<div class="blg-side-header">
<?php _e('Search on blog', 'blog'); ?></div>
<form class="nocsrf" method="POST" name="blg_search" action="
<?php echo osc_route_url('blg-action', array('blgPage' => 'search')); ?>">
<input type="text" name="blgSearch" id="blgSearch" value="
<?php echo osc_esc_html(urldecode(Params::getParam('keyword'))); ?>"
required/>
<button type="submit" title="<?php echo osc_esc_html(__('Search', 'blog')); ?>">
<i class="fa fa-search"></i></button>
</form>
</div>