Openwrt installation service or where to buy 4g router with openwrt?

Hi!

I have: ZTE MF286 and ZTE MF286D. I was reading instalation instruction and it is too advanced for me (and some USB tool needed?)

I need a 4g routers with latest version of openwrt and GUI (LuCI?). Is it possible to buy router or order instalation to my routers? Or maybe someone want to sell mf286d with openwrt?

PS located in Estonia

Thanks

Probably cheapest option is to buy 4G usb2.0 modem and plug in common routers USB2 port (or 5G USB3).

Or buy whole kit like turris/fritzbox/mikrotik

Or buy one with extension slots like banana or raspberry cm and add modules on it.

For reviving ones you have you will need USB serial adapter, commonly found in iot stores next to arduinos and raspberies.

As far i know/remember, USB modems have challenges with 4g signal strength and quality. Which combo you recommend? I mean USB + router?

PS i have one Mikrotik chateau lte12 also, but i didnt found, that is possible to use with openwrt

You can use your MF286D in a bridge mode with any router of your choice. Recommended firmware version is Nordic_B12.

Any link/instruction how to update to Nordic_B12?

You need to google it, that is unrelated to OpenWrt.

You kind of got all the options, mikrotik's model number like RBD53G-5HacD2HnD-TC&EG12-EA is just a list of pieces bolted together. But they support RB* with their firmware for like 10 years.
USB plug has the reception of a phone of that era, you need one worldwide unlocked, so it accomodates new band licences in your place instantly.