Airplay to speakers requires code

My iPhone 12, I’m able to Airplay to my speakers without a problem. I don’t have to pair it with Bluetooth. I just go to airplay and find the speaker and play music. On my iPhone 11, however, when I try to AirPlay to the same speakers, it’s asking me for a code. This isn’t a TV so I can’t see a code on speakers. Why is one iPhone’s Airplay working but the iPhone’s 11 AirPlay is not working?