excellent question – but a rather long answer….
When eaDocX re-generates your document, all the contents of each section are deleted, then replaced. So, conventional Word change-bars wouldn’t accurately show what has changed.
You have two options:
1 – Using eaDocX Change Marking: this adds a color of your choice to elements or diagrams which have changed since a date you specify. I usually set this to the publication date of the last version. See help at https://store.eadocx.com/help/index.html?change-marking.htm

2 – Use eaDocX Corporate Edition Document Management. This will create a whole new document each time you re-generate your document, if you choose to up-version it. So you can then use either the native Word ‘document compare’ function, or the simple front-end which eaDocX applies to the same function, to produce a document will all the change-bars you need. This will give much finer-grained control over the visibility of changes, down to the last comma or full-stop. see https://store.eadocx.com/help/index.html?document_management.htm