Ok, so I guess you have set up and connect to the camera using i.e. 192.168.1.108 when it works. That's your local IP and will not work to connect from the 'outside'.
Basically you have two options.
1.) Set ut port forwarding
2.) Set up an VPN
VPN is the better alternative if you want a more secure solution. It is often more complicated to set up - depending on you router.