WhatsApp <-> Signal interoperability

Hi all,

Since about 5 years I've got a Signal account and with little success tried to convince ppl around me to move over.

We all know the reason: WhatsApp works, so why bother?

But, being in the EU, since a few months or so, Signal users should be able to message with WhatsApp users, as per articles such as this one below.

What I cannot find however, is any how to make this work? Or is this just working today and I'm ignorant about it?

Cheers