CLI Features implemented in GUI

On Synology I can Syncthing manually start, stop, restart with the synoservicecfg command. E,g, start with

synoservicecfg --start pkgctl-syncthing.net

If I try to start --reset-deltas in that way

synoservicecfg --start pkgctl-syncthing.net --reset-deltas

it doesnt run. What is wrong?