Iphone SMS is displayed on ipad.

This information can be synchronized through icloud.

Open the phone settings, click AppleID, click iCloud on the AppleID page, turn on the switch behind the message, turn on the phone, return to the ipad, connect to the Internet, and wait for the information to synchronize. After syncing, you can view iphone information on the ipad. Ipad and mobile phone are also set up in this way. In information, preferences and iMessage information, the Mac checks Enable iCloud cloud information.