I am using google app engine for nodejs application deployment using https://cloud.google.com/appengine/docs/standard/nodejs/building-app doc. my nodejs version is v10.14.2 and npm version is 6.14.8 port is 4000, export port using "export PORT=4000".
NOTE: could not get any response at the end it says network error.
Basically I made an instance and setup compute engine there and deployed it. It is working now, I am made app engine in the same project. so, I have deployed two instances on same project one(compute engine) is working and other(app engine) is not