Pray, how do I login to the same account on my second phone? Or do you mean you can link multiple computers to the account on your phone? In which case, I’m not running that on my old laptop.
Edit: I’ll answer my own question:
Multiple mobile devices … are not currently supported.
https://support.signal.org/hc/en-us/articles/360007320551-Linked-Devices
Switzerland is not an EU country…