Any idea on how to create or obtain certificate files

When I start the server, it has the following error:
(node:2651) UnhandledPromiseRejectionWarning: Error: ENOENT: no such file or directory, open ‘/home/hz/mediasoup/mediasoup-demo/server/certs/fullchain.pem’
at Object.fs.openSync (fs.js:646:18)
at Object.fs.readFileSync (fs.js:551:33)
at runHttpsServer (/home/honghaiz/mediasoup/mediasoup-demo/server/server.js:363:13)
at run (/home/honghaiz/mediasoup/mediasoup-demo/server/server.js:74:8)
at
at process._tickDomainCallback (internal/process/next_tick.js:228:7)

So I think I need to config the certificate files in the config file. How do I create the certificate if I only intend to run a server in a local network?

Open Google and search for “how to create a certificate”.

Thanks!
This page was very helpful