Thanks a lot, I have installed syncthing on OMV5 and it's running!
I have one more question for you.
I have installed syncthing via ssh logged as "root" and then I have run it via ssh as "user".
But after reboot of OMV5 syncthing doesn't restart and every time I have to log in as "user" via ssh and run it.
Is there a way to restart syncthing automatically after an OMV5 reboot?