How to Expand or Collapse Parts of a Word Document

Thank you so much! I’ve been trying to figure out how to do this for a while now.

I have new word with yearly subscription and it doens't have expand icon. Microsoft is making me angry.

Is this offered on Google Docs?

How do I add non-collapsible text after my last Heading? I just want a few lines to collapse, not the rest of the document.

My word does not have the arrow beside the heading to expand or collapse the heading