$ lsof -i :8080 | grep LISTEN
node 33328 z001922 30u IPv4 0x716bf89633a758d5 0t0 TCP localhost:http-alt (LISTEN)
The name “node” doesn’t tell you anything, to get the detail, use ps
like this
$ ps -ef 33328
230232752 33328 33326 0 11:46AM ttys002 0:52.82 node /Users/..path../react-scripts/scripts/start.js
The program at the file path is using port 8080.