Screen Sharing on different networks?

Help back to mac different network

I have the same problem screen sharing works on same network but as soon as I moved my imac to my parents house (different network, different city) I can not access the back to mac feature and screen sharing. it does not show up on the shared device. Please someone help me I have tried many things. All settings are correct. I need help I am so frustrated.
Thank you

 

You can use teamviewer. This requires you to give a different password everytime (unless you set it otherwise) and to install a client on your computer. Or you could use logmein which works through your browser. I use logmein most of the time but teamviewer may be better for a different situation. Logmein is good because you can use any computer without having to install anything to screen-share with a computer you have already set up.