Remote Access not available for my Plex server
I am having trouble accessing my Plex server from outside of my home. Whenever I am over a friend's house, the server is unable to be reached. When I go to Remote Access under settings, it tells me that it is not available outside of my network. I'm not sure how to fix this and I would love some advice on how to. I am somewhat of a rookie at Plex and computer knowledge in general, so I may need things spelled out for me. I have enclosed a Word document with a picture of what I see under Remote Access in the Plex server.
Thank you in advance for your help.