Installed OpenWrt and modem packages: usb-modeswitch, kmod-usb-net-cdc-ether;
I connected one huawei modem and it worked, I selected it in the interfaces, unfortunately this is not my modem, I needed to connect another one.
The modem from the screenshots does not work, the system does not recognize it as usb at all.
My router: tp-link TL-WR842N.
Amazon says the M150-2 is a Huawei E3372, is this correct?
If not the output of lsusb would help.
Plug modem into a desktop Linux and confirm it can connect to the Internet. Check desktop's kernel log to see which driver is used. Install the same drivers in OpenWrt.
If modem does not work with "big" Linux it is going to be difficult most likely impossible to make it work with OpenWrt.
Modems that start up as a storage device and need to be modeswitched can sometimes be reconfigured to always run in modem mode.
Unfortunately, I don't have a modem with me now. But I'll try to do it when he appears.