@shajek
Drivers for MS are on the Internet.
There is a project in which the author finalized the library and launched MQTT for sim5320. Here is the link: https://www.instructables.com/id/Remote-Control-and-Photo-Surveillance-Over-MQTT/ .
Only there Arduino M0 is used (for convenience of working with several interfaces of UART). And it even transfers the image from the camera through MQTT and 3G channel.