CMS

you have to add this code to the block or to the page

 {{block class="Magento\Framework\View\Element\Template"  template="{Vendor}_{Module}::pages/example.phtml"}}

Example 

{{block class="Magento\Catalog\Block\Product\ListProduct" category_id="50" name="home.products.list.custom" template="Magento_Catalog::product/list.phtml"}}