The populate Word document template creates a Word file as the output. You need to use the developer tab in Word to add text, choice, date fields to your Word file. It would be used for creating a form and filling it in. Here is an example of one being filled out from the data from a MS Form submission:
This is for a regulated process, so it ensures that the template is not altered when it is filled out. In the document library where the generated Word document is saved, metadata columns have been added to the list to make it easier to identify each submission. The update file properties action fills in those values:
End result:
