RPI4 install problems - SIM7000 NB-IoT and 2-CH RS485

Hello, spent significant time on both without much success, unable to find information on how to install drivers and software for these HATs for Openwrt - all the documents relate to the other versions of Linux.

I downloaded openwrt image, put it onto he sd-card, booted the system, connected system through LAN to the internet, performed rpi-sysup-online - all successfully.

With RS485 I have totally no idea how to proceed. Device files do not appear at all.

For SIM7000 device files appear (cdc-wdm and 4xttyUSBx), but none of them are able to communicate if I make new 'wan' interface in GUI, the error is "pppd: LCP: timeout sending Config-Requests" without even try to send any modem commands to the device.

Any ideas? Thanks!