The template file would be :
app/design/frontend/Namespace/theme/Magento_Theme/templates/your_folder_name/file_name.phtml
{{block class="Magento\Framework\View\Element\Template" template="Magento_Theme::your_folder_name/file_name.phtml"}}
The template file would be :
app/design/frontend/Namespace/theme/Magento_Theme/templates/your_folder_name/file_name.phtml
{{block class="Magento\Framework\View\Element\Template" template="Magento_Theme::your_folder_name/file_name.phtml"}}