how do i change the phone number on my iphone?

i updated my phone from an 11 to a 13 and my husband was updating from a 6. in order to qualify for a rebate his number was associated with the 13. i have transferred all my info from the 11 to the 13 but it still shows his number as the device number. if you call his number it rings on the 13. we transferred all his info from the 6 to the 11. when you call my number it rings on the 11.

how do i get my number associated with the 13 and his number associated with the 11.

Thank you for your help.