I want the kind of text message that can make other people’s phone screen black or flash by sending a text message.

You must want to make a joke with your friends. If so, you can make a picture that is all black, and then it can be a picture of red or other colors, and then use this picture as an MMS message. method to send it to a friend. When the friend opens the MMS message, the screen goes black (actually a completely black picture is displayed). In the same way, create one or the next picture in gif format (the kind of dynamic picture that fills the screen with stars), and send MMS messages to friends to have a splash screen effect.

If you really want someone else’s phone screen to go black or flicker, that’s a special behavior. Special behaviors use special methods. You need to learn code knowledge. I don’t know.