I’m using free CloudFlaire SSL in my application takolehapp.com and it is working fine and it is secured but the Facebook login returns this error “ Facebook has detected Takol Eh isn’t using a secure connection to transfer information”.
May I ask is this an feature for your Facebook app? Sounds to me like it is, as far as I’ve used that long time ago.
If so, kindly check below links and make sure your domain is working over HTTPS while using Cloudflare (and having configured HTTPS URL in the Facebook Developers for your Facebook App) so far: