In addition to syncing many files with my Mac, I need to offload at least 100GB of large projects so I can make more space on my hard drive. I know a tag "online only" allegedly exists to allow you to do this in DropBox but I have never seen it, no matter how much I right click, neither using the DropBox desktop app or the web portal. I'm using MacOS 15. Any tips for doing this correctly? Thanks!