Hey there, Leeanefoo.
If you connect your iPhone via USB cable for CarPlay, check out the following article to see how to set that up: Use CarPlay with your iPhone - Apple Support
If you still have issues, then this article has troubleshooting steps to take that may help resolve the issue: If you need help with CarPlay - Apple Support
If you do not use CarPlay and connect your iPhone to the stereo of your car, then the details below, from the following article has additional details that may help: How to connect your iPhone, iPad, or iPod touch to your car - Apple Support
"Connect using USB playback
- Restart your device and your car.
- Make sure that your device is unlocked and on the Home screen.
- If possible, try to connect using another cable or USB port. Check the manual that came with your car to learn how to connect an Apple device.
- Check your charging port for any debris or damage. Make sure that your charging cable is properly inserted into the port.
- Update your device.
- Make sure that your stereo is using the latest firmware from the car manufacturer. Check your car's manual for more information.
- Try playing audio from a different app. If you can't play audio from a third-party app, contact the app developer for help. If you can't play audio from an Apple app, contact Apple Support."
Take care!