Sat nav not enabled

[Cavo]

Hi all. Just bought a a3 cabrolet 15 plate and would like to knowhow to enable the sat nav?

 

Edited June 18 by Cavo

[thatukguy_james]

normally the nav button on the head unit or steering wheel

if you mean it didn't come with it and want to add it , then i have read some guy on eBay says SD cards with it on for around £200

[Cavo]

Thanks for your reply.

It has the relevant buttons but when we select it the screen says satellite navigation not enabled. I was  wondering if I just need a sd card or do we have to take it to audi?