the lan side network interface appears to be completely gone, so it doesn't matter what you put there, it still won't work.
tried a reset ... ?
if you manage to set the static wan side IP, as you need from the ISP, you could wget the openwrt file over internet.... OR put another router, that works with the ISP, between the SamKnows and your ISP.
Yes, it is. However, the current firmware is not the official OpenWrt and it almost certainly operates very differently since it is highly customized by the vendor.
You are not only missing the lan side network, but also the firewall and DHCP configuration files.
Either something is very wrong with that installation/configuration, or the vendor has done something very very different than normal.
I'd recommend resetting the device to defaults. You may be able to do this with the standard openwrt method:
firstboot -y && reboot
If that works, it will hopefully get the normal networking functioning properly so that you can upgrade to an official modern version of OpenWrt.
If you cannot get it to reset, you may need to ask the vendor how to reset it or how to get the normal networking to function.
I already did the reboot, I need to edit /etc/config/network, so that I have a static ip to be able to connect to WinSCP.
The router already comes from the factory with a bridge.
Previously your post showed that the dhcp and firewall files did not exist... if you reset properly, they should hopefully be there (unless there is something unique about how SamKnows built their firmware).
Please copy the output of the following commands and post it here using the "Preformatted text </> " button:
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