Hello,
MS Word requires adding an ActiveX button with a custom macro: https://answers.microsoft.com/en-us/msoffice/forum/all/how-do-i-assign-a-macro-to-a-control-button-in/3cde2ffc-d505-46c1-9ae7-702e5a5f9518
The current stable version of phpdocx doesn't support this kind of content.
If you need to get a content with an appearance similar to a button, maybe you can add a text box with a text link in it.
Regards.