I still can't send a text message after changing the card.

If you are a mobile phone customer of Unicom, you can try to do the following: (1) It is recommended to change the mobile phone number that can't send and receive SMS normally to another mobile phone for testing; If the mobile phone test still doesn't work, you can use this number to call the local Unicom manual customer service to see if the Chinese SMS function is enabled; If the Chinese SMS function is not enabled on the mobile phone number, it can be enabled through local customer service and manual customer service.