php - How to Force SSL on Google App Engine Flexible Environment

Question

Is there documentation showing how to force HTTPS on Google App Engine - Flexible PHP?

I tried placing secure on app.yaml and I had no luck.

I also tried in the nginx-app.conf placing this but no luck.

I also tried

set $test "";

if ($http_x_forwarded_proto = 'http') {
    set $test "http";
}

if ($test = 'http-non-cron') {
    return 301 https://$host$request_uri;
}

Other Option I tried

<?php     
     header("Strict-Transport-Security: max-age=31536000; includeSubDomains; preload");  
     exit();  
?>

but no luck.

Answer 1

Waitting for answers