Display the registration number in the document name

How to make a document name display its registration number?
In ELMA Designer, open a document type page, go toe the Description tab, find the Document Name Template unit and using the Insert Document Attribute button, add Record Card Attributes -> Registration Number. Save and publish the document type and restart the ELMA server. Next, open the web application and go to Administration -> Document Management -> Records Classification Scheme. Cancel publication of the classification scheme and change the settings of the category, where the documents will be registered. In the category settings you need to specify the name, index, numeration and select a number template - registration number. Check the Update Document Name box.