Why haven't there been any free online short messages recently?

After imessage is activated, sending imessage messages is free as long as the mobile phone has a data network. 1, activate imessage. Apple phone settings-information, as shown below, we will see the iMessage switch click to open. 2. Open the data network, set-cellular mobile network, and turn on the cellular mobile data switch, as shown in the figure. 3. Open the wireless network, set-wireless LAN, and then select the wireless network you want to join. In the case of WLAN, iMessage is sent through WLAN traffic, and in the case of no WLAN, it is sent through cellular network traffic. Because traffic is generally free or monthly, and the size of text iMessage is almost negligible, iMessage messages are free.