Question about Gigaset Comfort 500 A Duo (CH-Version)

If you press in the centre of the large row of buttons, the menu is displayed and the SMS symbol appears at the top left. Confirm with ok, no sending centre appears and then switch to the settings, confirm again with ok and select sending centres. To send SMS, the number of the SMS centre must then be programmed.

I have looked through the entire software structure again: SMS function not available.