An IMESSAGE dialog box appears on the iphone.

IMessage is an instant messaging software launched by Apple, which can send short messages, videos and so on. It has very high security, and it is said that even the FBI is difficult to decrypt the information in the message. Sending things to each other on ios devices is free. If you don't need them, click Settings, and then click Info. Turn it off. I hope it works for you. Thank you.