WiFi Calling

Hi there, 

My spouse is going to Portugal in a few weeks. 

Can I send my Portuguese SIM card which is still active with him and he activates WiFi Calling on it?

So basically my question is does it need to be activated on my device or can he put it in his phone to activate? When we left I never activated it so it does not work on my iPhone. Will my phone and my sim need to be in Portugal to activate or can he just take my Sim and Activate it? 

Thanks

André