Use the following code to insert the template block in WYSIWYG:
{{block class="Magento\Framework\View\Element\Template" template="VendorName_ModuleName::some-template.phtml" }}
Use the following code to insert the template block in WYSIWYG:
{{block class="Magento\Framework\View\Element\Template" template="VendorName_ModuleName::some-template.phtml" }}