This guide demonstrates how to use the dashboard subdomain manager to add a subdomain to your website.
First, select 'Subdomains' from the sidebar of your dashboard.
You should see a page resembling the one below:
To add a subdomain, enter your desired subdomain into the input field and click submit.
For example, entering 'test' will create the subdomain test.yourwebsite.com.
The subdomain, if available, will be set up automatically and connected to Cloudflare for you (you won't need to edit the DNS). A folder will also be created for it on the FTP server.
As shown below, the subdomain will appear in the 'My Subdomains' table. From here, you can delete the subdomain and access its files, using the quick link which will take you straight to the subdomain's folder in the file manager.