Update Firmware

Hi All,
I have an issue. I bought a new Iphone 12 and it will not bluetooth to my 2013 Hyundai Elantra Limited. But the phone will bluetooth to other items. I called Apple and they stated I need to update my firmware in my car. Have any of you had this issue? If so, how did you fix the issue?

We did my Dad's 2011 Optima .. they send you a USB and follow the instructions. Took say 35 minutes and you just sit there with the engine idling. No idea really if it would solve your problem though.