how to send message in flask socketio function and receive this message on flask socketio socketio?

Question

I want to receive a message sent from flask-socketio def in flask-socketio def or flask-non flask-socketio def in the backend

@socketio.on('save-audio')
def write_audio(data):
    emit('arg1', 'save')

@socketio.event
def my_custom_event(arg1):
    print('received args: ' + arg1)

def give_message():
    #how to give message?