How to check the balance on a sim card in a gsm gateway connected via trunk?

Question

Asterisk

Good evening forum users.
Please tell me how can I organize a check of the balance of sim cards in the gsm gateway.
FreePBX 13, Asterisk 13.10, GSM gateway Dinstar DWG2000C-8G.
Asterisk is in the cloud, the gateway in the office is behind NAT.
Everywhere I read that they use the chan_dongle module, but they write that the module works with Huaway 3G modems and via the USB port. I can't figure out how I can get the balance from a remote gsm gateway from a SIP client or via a web page or by letter.

Answer 1

You can check the balance in your personal account with the operator.
Or read the documentation for the gateway, it can send/receive SMS and USSD via its own API.

Answer 2

Those. in this case chan_dongle and these scripts won't help me?
Is via API the only option?