port set by appengine

app.js

@@ -235,7 +235,7 @@ app.get("/verify/:id", (req, res) => {
     });
 });
 
-const port = process.env.SERVER_PORT;
+const port = process.env.PORT || 8080;
 
 app.listen(port, () => {
     console.log(`Listening on port ${port}`);