step 1:- Go to your cPanel
step 2:- Go to the Domains section and click on Subdomains.
step 3:- Type in the name of the subdomain and select the domain to create it under. It will automatically create a folder for the subdomain in your public_html folder.
step 4:-Click the Create button. You will then see a message stating it "has been created."
step5:-it can take up to 24 hours for a new Subdomain to show up on the web, or propagate.