Under Sonos Radio, look under “Sonos Presents” or search for “Never Stop Exploring” under Stations in the Sonos app.

Thank you GuitarSuperstar.

However it does not work. Is that because I am in Spain?

I did not think that Sonos Radio would have region limitations as Netflix and so on...

Sonos Radio isn’t available in Spain.

Original stations are available in the United States, Canada, United Kingdom, Ireland, Australia, Austria, Belgium, Denmark, France, Germany, Italy, Netherlands, New Zealand, Norway, Sweden, and Switzerland.

Sonos Radio HD is available in the United States, United Kingdom, Austria, Canada, France, Germany, and the Netherlands.

https://support.sonos.com/s/article/4822?language=en_US

Not exactly.

Sonos Radio IS available in Spain. But not the original stations. I am in right now.

"Sonos Radio está disponible en todo el mundo.

Las emisoras originales están disponibles en..." 

So I have to assume that Never Stop Exploring is referred as an original one.

Thanks anyway for the help! Good listening!