Total beginner can't connect music

[Loops81]

Sorry if I'm being a total newbie but I bought an echo which I'm currently using for radio, reminders etc..
I joined up to amazon music but each time I say play a song it says to buy music... Which I already have.
I have downloaded the app to my phone but when I ask alexa to play something it plays it though my phone, and then I have two alexas responding to me 😂 
Please help x

[renegade600]

not all music is free.   are you an amazon prime member? 

[blackbeagle]

not all music is free.   are you an amazon prime member?

If you are a Prime member, what music would you be entitled to? What would you get free if you have Prime? I have Prime. I know that gets me some movie streaming. But I don't do anything with the music.

[renegade600]

not all music is free.   are you an amazon prime member?

If you are a Prime member, what music would you be entitled to? What would you get free if you have Prime? I have Prime. I know that gets me some movie streaming. But I don't do anything with the music.

you get free music too.

https://www.amazon.com/gp/help/customer/display.html?nodeId=201530920