I am running an Ubuntu instance on GCP with apache2 and php 7.
More so, I am using CloudFlare as my SSL certificate provider.

In GCP, if I configure "allow http and https", the website works both for http and https. Though I have to specifically add the https prefix to domain, so that it will work securely.

But, if I disallow the http in GCP, and allow only https, I am unable to enter my website whatsoever, even with adding the https prefix.

Is there any configuration I am missing in GCP or Apache2?

I'd appreciate your help.