Why is the Bluetooth transmission sent by the Nut 3 phone to the machine blank and cannot be loaded?

When the Nut 3 mobile phone sends a native Bluetooth transmission, it is blank. The reason why it cannot be loaded is because there is no correct connection between the mobile phones or a transmission failure. . According to the query of relevant public information, the mobile phones are not connected correctly, the mobile phone is jammed, the file is too large, the pairing is unsuccessful, etc., which will cause the file to be unable to be sent and received, and the file cannot be loaded. The correct connection method is to turn on the Bluetooth function of the two mobile phones, search for each other, click pairing, and enter the pairing code. After successful pairing, you can transfer files through Bluetooth. The transmission distance must not exceed 10 meters, otherwise the transmission will be interrupted.