Trying to add support for the LongSung U9300C Modem

Hi all, a newbie here...

I have a ZBT-WE826/KuWFI router on hand and I had been messing around with it lately. I am trying to get the SIM modem functionality on it to work for some time now but nothing has worked out so far. The router uses a LongSung U9300C TD-LTE mPCIE Modem. I had read a few Chinese articles online on how to use the GobiNet driver to add support to the U9300C but I never get past the point of selecting the Kernel Modules for USB Support in make menuconfig as well as modifying the file option.c under the folder /drivers/usb/serial.

I had followed the instructions on the "Using the SDK" and I had ran the commands ./scripts/feeds update -a and ./scripts/feeds install -a, I also thought I had screwed up somewhere and I had started the process from scratch for the 3rd time now, but the result is still the same.

My question is similar to this article , I was not able to see the modules named kmod-usb-acm kmod-usb-core and etc.

So up to this point, my question is that how to I get the option.c file (like am I supposed to download it somewhere or what), and how to get all the kernel modules for USB (i.e kmod-usb-acm, kmod-usb-core) because I don't see them in make menuconfig?

Here are the 2 Chinese articles I tried to follow:

The version and platform of the SDK I am using is openwrt-sdk-22.03.2-ramips-mt7620_gcc-11.2.0_musl.Linux-x86_64

Thanks first!

Just another photo to illustrate what I am seeing
The only 2 modules I can currently see in Kernel Modules>USB Support are only these:

what does lsusb say about the modem ?

lsusb recognises the modem itself, listed as " Bus 001 Device 003: ID 1c9e:9b3c LONGSUNG USB Modem"
I will also attach a screenshot from cat /sys/kernel/debug/usb/devices would indicate you should use the option driver ?

Yea I know I need to use the option driver. But do I copy the one directly from here and just modify it according to the article and put it into the drivers folder?

Hi Oyan244,
Did you succeed in flashing the Longsung U9300 driver?
I also have a Kufwi 4g router with the same module. I have also tried but did not succeed.