@Black Mamba @Thegiesio84 if it is an Internet Box 3, you will also need a fibre kit.
This contains an SFP module for the 1Gbit/s fibre connection (BX) and the fibre connection cable.
**But if you have a 10 Gbit/s (XGSPON) you need the IB 4 or IB 5 Pro. This automatically includes the connection cable for the router to the OTO socket (fibre optic socket).
Swisscom SAP No. 10184338 “Upgrade Kit Fibre Internet-Box ” you must order this free of charge on 0800 800 800 or order here
https://www.swisscom.ch/de/privatkunden/hilfe/kontakt.html#cascadingTabs%5Binner%5D=tab_1643987701661&cascadingTabs%5Bouter%5D=tab_1643984309833
