We have not tested a 4G camera. Reolink has 4G and/or battery-powered IP cameras with solar panel. The problem is: A battery-powered IP camera is usually in standby/sleep mode. It cannot record/work continuously. While techically it is possible for the camera to wake up periodically and upload an image(s), unfortunately Reolink battery-powered IP cameras can only support motion-triggered recording. If it works for you, you can watch this video for more detailed info about how to configure it:
https://www.youtube.com/watch?v=B6KzFLC1p0k
Otherwise, you might want to use a smartphone as an IP camera and use CameraFTP Mobile Security Camera app. Please watch this video for more details:
https://www.youtube.com/watch?v=9cLPm1BmPv4