I'm not very experienced in hosting servers, so I apologize for any left out details; feel free to tell me what I'm missing and I'll provide it.
I'm using cloud.linode.com to host this GitHub repository. It's a Pokemon simulator that runs on JavaScript in NodeJS. I created a fork of the original website's repository and slapped it onto a cloud host; following the original Git's instructions for hosting your own copy of it, which really just consists of installing all of the necessary packages. Once I'm done, and I boot up the server, I can join it locally, but I cannot connect to it via the IP address Linode provides me, nor can any of my friends. I've also tried hosting it locally in a folder on my machine, starting it through the terminal, and port forwarding, or using a program such as ngrok, which gives you a link that redirects to your localhost website, allowing anyone to access it; same problem. I can join the server locally, with localhost:8000, but through the provided link or IP address, I get this error in Chrome:
I can't request an SSL certificate, as the link to connect to the server is just an IP address, not a domain. Notably, connecting to the server will occasionally work through the link/IP, but not typically. Sometimes, if you spam the "reload" button in your browser enough, or switch between browsers a few times, or try connecting in Incognito Mode, it will connect; but if you try again, it no longer will. It seems completely random and I cannot find any variable that correlates to it occasionally working, and then not immediately after. I'm in desperate need of help; again, let me know if there's any necessary information I've left out and I'll do my best to provide it. Thanks.