Urgent! Please Help

[fritex]

@dineshiitb.ae18

subdomain is showing the error DNS_PROBE_FINISHED_NXDOMAIN.

May I ask if you have an CNAME or A record for your sub-domain study.piacademy.co.uk?
Also, is the DNS record for that sub-domain or cloud?

Moreover, what SSL option have you got selected at Cloudflare dashboard? (Flexible SSL, Full SSL …)

Have you had an SSL certificate already installed at your host/origin server?
If yes, does the SSL certificate cover your sub-domain hostname?

Here are the steps regarding the DNS_PROBE_FINISHED_NXDOMAIN:

Community Tip - Fixing the DNS PROBE FINISHED NXDOMAIN error

Error Try the suggestions in this Community Tip to help you fix DNS_PROBE_FINISHED_NXDOMAIN. Background NXDOMAIN stands for non-existent domain. When a domain cannot be resolved it is an issue with the DNS servers or the domain name is newly registered or not yet registered at all. NXDOMAIN can also take place due to network or DNS server problems. A response other than a valid IP address (e.g., timeout, SERVFAIL, NXDOMAIN or NOERROR) most likely points to the origin as the source of your iss…

Moreover, as tested, I got 521 error.
Have you tried looking for a fix here?
Kindly, follow the steps in the article and the post from below to solve your issue:
https://support.cloudflare.com/hc/en-us/articles/115003011431-Troubleshooting-Cloudflare-5XX-errors#521error

Community Tip - Fixing Error 521: Web server is down

Error Try the suggestions in this Community Tip to help you fix Error 521: Web server is down. Background A 521 error happens when we are unable to make a TCP connection to your origin server. Specifically, Cloudflare tried to connect to your origin server on port 80 or 443, but received a connection refused error. This is often caused by security or firewall software and happens if the origin server has directly refused Cloudflare’s proxy request. [Banner in tip catalog] Quick Fix Ideas …