Satyajit
please try one thing. In your forum root folder, there is a file called config.php.
You will see among some, something like this:
'collation' => 'utf8mb4_unicode_ci',
'prefix' => '',
'strict' => false,
),
'url' => 'http://wehindi.com',
'paths' =>
array (
'api' => 'api',
'admin' => 'admin',
),
);
Edit the 'url' so it reads
( or similar - Important part is that http:// becomes https:// )
If this does not work for you, I will put up a test domain later tonight, installing Flarum originally without SSL activated, then add cloudflare with SSL enabled, and see what happens.