Suggestion, buy the thing (Tradfri) from Ikea, it has Swiss plugs and can be added as an on/off switch after the reset under lamps.
I only have experience with the Hue bridge, and it works fine there. But since Ikea also works with Zigbee, it should also work with Osram.

How is that possible? Are they only adapters? Does it work with the "Innr Smart Plug SP 120"? Or is the same problem here?

It says in the product description: does not work with adapter. Digitec should have taken this plug out of the range long ago! Only works in Germany!