I was able to achieve that by adding below to theme file:
$this->output('<div class="sharethis-inline-share-buttons" data-url="'.qa_opt('site_url').str_replace("./","",$q_item['url']).'" data-title="'.$q_item['title'].'"></div>');
Also setup buttons on sharethis.com and add below code to site header
<script type='text/javascript' src='https://platform-api.sharethis.com/js/sharethis.js#property=xxxxxxxxxx&product=inline-share-buttons' async='async'></script>
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