I missed the fact yours is an 04. I think at that point not all cars had a BT module. Maybe a dealer could tell you, or as suggested, pop the speaker grill off behind the drivers seat and take a look for a passcode. If you don't see the code you likely don't have the module. Easy fix with a Grom unit if you don't and that would be better anyway since it adds streaming to the mix.
https://www.newegg.com/p/0H9-00J1-00...B&gclsrc=aw.ds