How to set "LTE only" in openwrt?

Is there an option to set the network mode to LTE only when using a usb dongle ? My LTE signal is a little weak so it keeps switching to 3G instead of LTE, I want it to use LTE only instead of 3G. How can I do that ? With 3G only you can use “umts_only” in /etc/config/network but I don’t know about LTE

I don’t know if there is a general method.

Maybe you need to check instructions of your modem, in case there is an AT command