def func(self):
        caller = self.caller
        channelkey, msg = self.args
        if not msg:
            caller.msg("Say what?")
            return
        channel = ChannelDB.objects.get_channel(channelkey)
        if not channel:
            caller.msg("Channel '%s' not found." % channelkey)
            return
        if not channel.has_connection(caller):
            string = "You are not connected to channel '%s'."
            caller.msg(string % channelkey)
            return
        if not channel.access(caller, 'send'):
            string = "You are not permitted to send to channel '%s'."
            caller.msg(string % channelkey)
            return
        msg = "[%s] %s: %s" % (channel.key, caller.name, msg)
        msgobj = create.create_message(caller, msg, channels=[channel])
        channel.msg(msgobj)
Create a new message and send it to channel, using
dataset/ETHPy150Open evennia/evennia/evennia/commands/default/syscommands.py/SystemSendToChannel.func