How do you synch your joplin files on a private way?

So for the joplin users here:
i want to sync joplin files between my phone and desktop.
But what i understand is (correct me if i wrong) that sync targets (clouds like dropbox and onedrive) that joplin advised are not privacy safe to use.
Then there is Syncthing but this is not working well with joplin.
Protondrive can’t be used because it is not using api…

So what is left? Buying my own NAS for building my own private cloud?

If you enable EE2E and use a strong password, it shouldn’t matter much which cloud provider to use.

You could do a really fancy sneaker net with Joplin’s File System Sync to a second directory on each device, then syncthing or similar to swap those directories between your devices. Then File System Sync on the other Joplin/device and it should be up to date.

No cloud solution needed, risk of conflict (if you edit a page in both places without syncing) and maybe a bit tedious, but you are in control all the time.

The Joplin docs have steps to enable and disable encryption. I’d recommend a backup just prior embarking on such a journey.