Tutorial - Using Cellular Modems with the Raspberry Pi 4B - SwitchDoc Labs Blog
3. Installing 4G USB modem to Raspberry Pi – RC Bellergy's Drones
Raspberry Pi 3G/4G & LTE Base HAT
Amazon.com: 4G / 3G / GNSS HAT Module for Raspberry Pi Zero/Zero W/Zero WH/2B/3B/3B+/4B/Jetson Nano, Based on SIM7600A-H , 4G Communication and GNSS Positioning Module Support LTE CAT4 up to 150Mbps :