both url works fine
HTTP
curl -X GET http://vikas-tradeassist.appspot.com -v
Note: Unnecessary use of -X or --request, GET is already inferred.
* Rebuilt URL to: http://vikas-tradeassist.appspot.com/
* Trying 216.58.209.20...
* TCP_NODELAY set
* Connected to vikas-tradeassist.appspot.com (216.58.209.20) port 80 (#0)
> GET / HTTP/1.1
> Host: vikas-tradeassist.appspot.com
> User-Agent: curl/7.52.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Content-Type: text/html; charset=utf-8
< Vary: Accept-Encoding
< X-Powered-By: Express
< ETag: W/"16-G3QRnkGnzs/eUFV3dBJOp3abMcQ"
< X-Cloud-Trace-Context: 4372bde851cfd9557f36a75fef42a48c;o=1
< Date: Mon, 30 Dec 2019 09:17:32 GMT
< Server: Google Frontend
< Content-Length: 22
<
* Curl_http_done: called premature == 0
* Connection #0 to host vikas-tradeassist.appspot.com left intact
Hello from App Engine!
HTTPS
curl -X GET https://vikas-tradeassist.appspot.com -v
Note: Unnecessary use of -X or --request, GET is already inferred.
* Rebuilt URL to: https://vikas-tradeassist.appspot.com/
* Trying 216.58.209.20...
* TCP_NODELAY set
* Connected to vikas-tradeassist.appspot.com (216.58.209.20) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
* CAfile: /etc/ssl/certs/ca-certificates.crt
CApath: /etc/ssl/certs
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
* ALPN, server accepted to use h2
* Server certificate:
* subject: C=US; ST=California; L=Mountain View; O=Google LLC; CN=*.appspot.com
* start date: Dec 3 14:40:31 2019 GMT
* expire date: Feb 25 14:40:31 2020 GMT
* subjectAltName: host "vikas-tradeassist.appspot.com" matched cert's "*.appspot.com"
* issuer: C=US; O=Google Trust Services; CN=GTS CA 1O1
* SSL certificate verify ok.
* Using HTTP2, server supports multi-use
* Connection state changed (HTTP/2 confirmed)
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
* Using Stream ID: 1 (easy handle 0x55e9c0d28d00)
> GET / HTTP/1.1
> Host: vikas-tradeassist.appspot.com
> User-Agent: curl/7.52.1
> Accept: */*
>
* Connection state changed (MAX_CONCURRENT_STREAMS updated)!
< HTTP/2 200
< content-type: text/html; charset=utf-8
< vary: Accept-Encoding
< x-powered-by: Express
< etag: W/"16-G3QRnkGnzs/eUFV3dBJOp3abMcQ"
< x-cloud-trace-context: 80c7b7e158f3d517a65a2608e6b67b68;o=1
< date: Mon, 30 Dec 2019 09:17:51 GMT
< server: Google Frontend
< content-length: 22
< alt-svc: quic=":443"; ma=2592000; v="46,43",h3-Q050=":443"; ma=2592000,h3-Q049=":443"; ma=2592000,h3-Q048=":443"; ma=2592000,h3-Q046=":443"; ma=2592000,h3-Q043=":443"; ma=2592000
<
* Curl_http_done: called premature == 0
* Connection #0 to host vikas-tradeassist.appspot.com left intact
Hello from App Engine!
if problems occur in the browser, try to clear browser cache, use browser with open dev tools [F12] with disabled cache option, see: https://superuser.com/a/304600