Use conditional tags
You can hook in a div for AddThis using conditional tags and WordPress or theme specific hooks from your functions file.
Hook Buttons in Using Custom Function
In this example, wp_footer
function wpsites_function() {
if ( is_single(array( 1, 2, 3, 4, 5 ) ) ) {
echo '<div class="addthis_native_toolbox"></div>';
}}
add_action('wp_footer', 'wpsites_function');
Change wp_footer to any other WordPress hook position or theme specific hook.
Add Code In Template
You could also add the code with conditional tag directly to your child themes single.php file in the position you want the buttons to display.
Load Javascript for Buttons
You’ll need to load the js for the AddThis script on every page you want the buttons after you create you own account and use your own publisher i,d in the code.
<!-- Go to www.addthis.com/dashboard to customize your tools -->
<script type="text/javascript" src="https://s7.addthis.com/js/300/addthis_widget.js#pubid=ra-52f6368a531ddc3b"></script>
You can do this using wp_enqueue_scripts
Or use the Header and Footer scripts box your theme includes.