For review stars on your product pages use this:
<div id='opinew-stars-plugin-product'>{% render 'opinew_review_stars_product' product:product %}</div>
For review stars on your collections/product lists pages use this:
<div class='opinew-stars-plugin-product-list'>{% render 'opinew_review_stars_lists' product:product %}</div>
For the review widget:
<div style="clear:both;"></div><div id="opinew-reviews-product-page-code" class="">
<span id="opinew-plugin" data-server-address="https://www.opinew.com" data-opw-prodreviews="{{ product.metafields.opinew_metafields['product_plugin'] }}" data-opinew-shop-id="{{ shop.id }}" data-shop-url="{{shop.domain}}" data-platform-product-id="{{product.id}}">
<span id="opinew_product_plugin_app"></span>
</span></div>
If you happen to have any issues with manually adding Opinew code, feel free to contact our support center.