To Install a subdomain under your root domain name, you must access the Domain registrar admin panel and DNS configuration Settings. As well as you will need the access of the cPanel where your domain name located you want to make a subdomain.
Steps to Install Subdomains:
First of all, go to your cPanel by login in using your Email and Password. Suppose will create a subdomain under domain name “http://progracoding.com” and the subdomain will be “http://test.progracoding.com”. Ok, after login into your cPanel, Now locate for a option “Subdomain” click on it and enter the subdomain name into subdomain field under Create a Subdomain option. (here subdomain is test, replace yourself to your desired name. Then Select your root domain name. After that choose a location in public_html folder where your all files and script will be store. Follow the image below:
Make sure you have the test folder created in public_html. Perform this before this action. No go cPanel Home and find and select the Zone Editor Option. Under zone editor click on manage button. Now you will see some A record and some TXT record added automatically under test.progracoding.com . Follow image below.
In the hidden area there are some ip address you will need later. So keep the window open. Now in a new tab go to your domain registrar admin panel and those cPanel value(A and TXT record) in the DNS settings. Click on save button. You have successfully added “test.progracoding.com” subdomain in your server.
If I use a CDN?
If you use a CDN (Content Delivery Networks) like Cloudflare you will need to modify on your Cloudflare account in order to optimize you subdomain with CDN.
Just Add a CNAME record in your Cloudflare account under DNS settings. Follow image below;