How did my mobile phone group send short messages to MMS? Is there any way to set up short messages in groups?

How to turn SMS sent by Android phone into MMS: First, check whether the "Subject Bar" is opened in the SMS editing interface, and press the menu button to close it; 2. Enter the SMS settings to see if there is an option of "converting SMS into MMS" and turn it off; 3. Enter the SMS settings to see if there is an option of "Remind when SMS is converted into MMS" and turn it on; Fourth, send long short messages through third-party software (search short messages in any application market, and choose to download, install and use them according to personal needs).