Can't you send a message by learning from a powerful country?

What I understand is that the chat section of a powerful country can't send out information. If there is, we can exclude it from some aspects. For example, there may be problems with the network and signal, which makes it impossible to send information. Try whether other software can be distributed, and rule out the reasons of the mobile phone itself. Or ask students if they can use it normally, perhaps because their learning ability is in the revision period and they can't send it? Or send a message to another friend and see if you can send it. If so, it should be that the other party has set a refusal, and you can't send it out. However, if you can't send a message by changing friends, you can ask the customer service for specific reasons, or you can try to uninstall this software first and then download it again.