Hi Bartosz,
Does (the supplier of) the camera has an api/webservice where you can interact with?
Nest and Ring does have some api's where can you take pictures etc. Also other security systems, almost all the time based on a service.
So I would say ask the supplier how to connect from internet to the device.
And from there it is actually Standard Operation Procedure from within Mendix where you can get the image over the service.