Access when away from home wlan

[Securityminded]

I am sorry for this very basic question but I couldn't find the answer by searching.

I have ip cam viewer ver 6.3.8 installed in a nexus 5 running stock 5.1.1.
When I am at home on my home wlan I can see all the zmodo cameras. But when I am away from home ip cam viewer cannot show the cameras and all I get is "camera feed unavailable" What do I need to do to view the camera display when I am on
1. On a different wlan?
2. No wireless available, just phone data plan?

Thank you!

[Securityminded]

No support?

[N4Spd]

ddns setup

see: https://hit-mob.com/ip-cam-viewer-android/faq/#2

I am sorry for this very basic question but I couldn't find the answer by searching.

I have ip cam viewer ver 6.3.8 installed in a nexus 5 running stock 5.1.1.
When I am at home on my home wlan I can see all the zmodo cameras. But when I am away from home ip cam viewer cannot show the cameras and all I get is "camera feed unavailable" What do I need to do to view the camera display when I am on
1. On a different wlan?
2. No wireless available, just phone data plan?

Thank you!