runtime error

/app/server.js:29 app.listen(port, (y) => {console.log(`Reverse proxy app running on ${baseUrl}`); ^ ReferenceError: port is not defined at Object.<anonymous> (/app/server.js:29:12) at Module._compile (node:internal/modules/cjs/loader:1256:14) at Module._extensions..js (node:internal/modules/cjs/loader:1310:10) at Module.load (node:internal/modules/cjs/loader:1119:32) at Module._load (node:internal/modules/cjs/loader:960:12) at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12) at node:internal/main/run_main_module:23:47 Node.js v18.16.1

Container logs: