Setting Up Internet Connection with LTE Modem and OpenWRT Router

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello, due to necessity, I have to use the internet via an LTE modem. My LTE modem is a Huawei B618-22d and my router with OpenWRT is a Zyxel NBG6617. I want my LTE modem to only provide internet, but it doesn't have a bridging mode. How can I set this up most easily on my router?

2

You can't.

Run your Openwrt router as dumb AP, or double NAT.

3

I don't know much about these things. Is Double NAT problematic?