Hello,
You need to use the CreateDocxFromTemplate class to use the template methods. This class inherits CreateDocx.
We recommend you to check the included samples in the package, the API page (https://www.phpdocx.com/api-documentation/templates/replace-variable-html-Word-document) and the practical guide (https://www.phpdocx.com/documentation/practical/working-with-templates).
Regards.