If your iPhone 12 uses wired headphones, you'll need to use a Lightning connector converter. This means you can only use one Lightning port to connect and charge your headphones at the same time. You can consider using a wireless charger or a Lightning charging cable connection adapter for charging. In addition, you can also consider using Bluetooth headphones, so that you do not occupy the charging port, you can listen to music and charge at the same time.
That's right. Just pull the headphones out and charge them