Hertz

Hello I wanted to modify a Mikrotik LHG LTE Router/Modem, in order to make it work with an EM7565 LTE modem instead of the originally built-in modem, and OpenWRT installed on a Raspberry Pi 3 (since RouterOS doesn't support the EM7565). But I have another requirement, I don't want the router functions of OpenWRT, I only need a bridge mode (IP Passthrough), the routing is done by an Ubiquiti ER-X-SFP. I have tried with OpenWRT + Rooter, but I couldn't make the bridge mode to work. I have noticed a few pages before that some people arrived to manage it with OpenWRT + ModemManager, but I have no idea how to do it. Can someone help me please? - How do I integrate ModemManger to OpenWRT (I haven't found it in the menuconfig) - How should I configure it to make the IP passthrough to work? Thank you!