I can not connect a 3G USB modem to Khadas (Android 6.0)

I need to use 3G USB modem (Huawei) to get mobile internet in Khadas.
But I can not connect it. The Khadas (Android 6.0) does not see the USB 3G modem.
How to solve this problem?

What’s the model of 3G USB modem (Huawei) ?
It need to add special rild library to system and start that service.
Also May be need to add the vendor id and product id into usb driver.

Maybe in future versions you could include support for an specific 3G/4G dongle, so there will be support out of the box.