Connecting Home assistant through 3g usb modem

Hi all, I’m a happy user of HA since 3 years and now I’m trying to setup a new installation in my new RV-truck

I’m using a Rasp Pi 4 + router with 3g capability + 3g usb dongle

the first appoach has been to use a 3g router with th usb modem but i wonder if i can use somehow the 3g usb dongle directly on the raspberry pi

any help welcom

thanks in advance

Paco