Fixed text element
A fixed text element is used to put text in the template that can only be written at the template level. So this text cannot be modified by a document writer. A fixed text element can for example also contain a smart field.
For more information, you can check out this article.
To add a fixed text element, hover the mouse over the element where you want to add it and click 'Fixed text'.
Here, as a template writer, you can now insert the text.
The text element from the document: