First off, love your service! Thank you for doing it. I have shared hosting on Opal3.
I'm midway through turning an R script into an API endpoint using R plumber. Following these instructions, I have successfully done things such as starting a PHP-Apache app in Opalstack, linking it to an Opalstack Domain and Site, installing R and Plumber, installing pm2 process manager, and startup/start of pm2. For example, I verified that my R file is actively running as a pm2 process and it is decorated with the necessary Plumber annotations.
But I'm running into a roadblock at the point that says "Wrap Your Plumber File." This step consists of running a command which activates a Plumber API running on host 0.0.0.0 (any IP4 connection) and port 4000 (i can choose anything).
Functionally I know how to execute this step, and I think I did it. However, at this point I believe I am supposed to be able to test by viewing the output of my API endpoint on a URL like http://my-app.my-account.opalstacked.com:4000/my-endpoint
However, I'm getting "This site can't be reached - ERR_CONNECTION_TIMED_OUT" when I try to view my endpoint URL.
My question is: Do I need to open this port (e.g. 4000) on Opalstack in order to allow external connections to that port? [FYI i can choose any port]