Error when creating website with ssl at digitalocean .plz help

Starting SSL verification.
Warning: Server error: GET http://findtopreview.com/.well-known/acme-challenge/QUD-w1lGGGffyMlABJF8zPGo7jM4i8eCdVyPF2YokTk resulted in a 521 Origin Down response:

<html class (truncated...)

ok , i did it myself . just added . cloudflare ips to digitalocean firewall.

Please help! my website Safe tricks is hosted on Digital ocean. i m also usin cloudfare cdn and it’s shared SSL. but, its creating redirection loop. tell me how can i fix it?