OpenWrt on Huawei B818-263

Hi all , is it possible to install the openwrt firmware onto a huwaei B818-263 device ?
or other Huawei device supporting 4G LTE or 5 G ?

Usually, no.

Depends on chipset though.

Nothing from Huawei found: https://openwrt.org/toh/views/toh_lte_modem_supported

I've got one of these they are fantastic. Just set to bridge mode and buy an RT3200 router with OpenWrt.

As an alternative to the above you can also buy RT3200 and cheap android phone with SIM in phone then tether phone to RT3200 over usb.

Works perfectly fine with the only problem being SQM with variable rate connection since CAKE's autorate-ingress doesn't work and there are only DIY hacks to try to make it work.