Fix Cloudflare issue on FusionPBX server

I installed to my local server FusionPBX, it's working well, but since I want to access it remotely without exposing it to the internet with port forwarding, so I used cloudflare, I installed cloudflare by following the steps in my account for port 443 but the issue is that when I open it on my domain it's opening the login page but when I add the username and password it's not entering to the dashboard so what's the solution for that?

Please bid only if you know both Cloudflare and FusionPBX