Nubian's mobile phone will automatically send text messages when it doesn't answer the phone. How to turn off this function?

This is a service provided by network operators. You can ask the network operator to cancel the service for you.

This function needs to slide up on the call interface to select the information content to be sent. If you hang up normally, you won't send a message.

You can tell the operator that they will operate according to your situation and turn off this function.