How to register number for iMessage?

I want to add contact phone number to iPad message. They are on iPhone but not ipad

Hi JesWannaNo,

to use your number for iMessage you will have to go to Settings->Messages and turn on iMessage.

To learn a little more about iMessage you can go to this site:

https://support.apple.com/explore/messages

However if you want to add a number that you can use for iMessage on your devices you will have to go to Settings

->(your Apple ID card at the top)->Name, Phone Numbers, Email and press „Edit“ next to „Contactable At“ and add another number.