How to sync a folder instead of creating a collection of a folder then sync it?

I have subscripton of lightroom and photoshop (20GB) and what I need is a very simple job, to sync a folder with constantly changing contents so I can view them on my iPad and every changes I make on my Macbook will reflect on my iPad.

In lightroom it looks like it needs to be a collection before I can sync it.  But if it's converted to collections, changes made to the folders will not be synced to the collections, meaning every time I add a photo or move it to another folder, I need to make it a collection and sync about 3000+ photos again ~? 

There's must be a very simple way of doing this but I couldn't find ... anyone has any ideas?  THanks in advance 🙂