Radio Head Unit Upgrade

[barfly1959]

I have upgraded the head unit in my 2013 Caddy Van from an RCD 215 to an RCD 310. All the functions work except Bluetooth music streaming. I can make & receive phone calls using the controls on the RHS stalk. How do I get the music to stream? What do I need to have fitted?

I believe I need some kind of Bluetooth modulke but unsure which one ..............