Sync documents between Mac and iPhone

Hi guys, is it possible to sync documents and folders from my Mac (El Capitan) to my iPhone (iOS 13) via the Files app so that if I make any amendments to a particular document or create new documents on the Mac it automatically syncs to my iPhone?

I have a folder stored on the HD of my Mac which has a mix of Word and Excel documents, which I would like to automatically sync over rather than me have to drag and drop overtime I make an amendment.

I checked this page on Apple's site, but it doesn't work for me https://support.apple.com/en-gb/HT206985