@elusive, thanks for checking into that. One of the core issues with iCloud (and it’s one of being in opposition to the core design philosophy of Joplin) is that it is limited to only Apple platforms. There’s almost no real way that I know of to access iCloud content directly on Windows or Linux. Apple also doesn’t allow direct access to their iOS file system, making using File System Sync not exactly a viable option either.
If you are interested in using iCloud for your notes and are exclusively locked to the Apple Ecosystem, you might be better off moving to a note-taking app such as Bear. Other than that, the devs here would be much better suited to explaining this more.