Transfer number to another I phone

I transferred my old I phone XR to a new iPhone 13 via the Bluetooth mode. I keep getting the message display that says - “ transfer A phone number from this iPhone to your other I phone “ on my new iPhone 13. What is this problem and how do I solve it. Please help. I don’t and have never used an e sim. I had removed my physical sim from the old iPhone XR to the new I phone 13.