chan_dongle is only community supported, and I’m not sure if there is any expertise here, however, it looks like DongleSendSMS() takes all the necessary parameters, so you should be able to use originate with it as the application. You will need some stub dialplan to allow you to provide a local channel on which to run it.
Or did you not really mean an SMS, but rather a SIP message, which an ITSP or gateway might turn into an SMS?
Also, you have asked two questions about SMS; I find it difficult to believe they are totally unrelated, and justify separate threads.
message.c doesn’t define any CLI commands, and you need at least two lines of dialplan to send a message, so you would need some non-trivial dialplan, to support an originate call and put everything together.