For creating subdomain structure for your short link . You need to create a subdomain from your cPanel with your subdomain folder . and later you need to set wildcard Wild Card Redirection from your subdomain to your root domain . and letter add subdomain keyword in custom subdomain template in Exact Links .
Create An Subdomain
Lets create custom subdomain with folder where all documents will be stored for subdomain .
Step 02 [ Wild Card Redirection ]
lets set Wild Card Redirection for your custom subdomain
Step 03 . Now Add Custom Subdomain Structure In Your Subdomain
Now add the subdomain keyword in Exact Links custom subdomain template , all done . your custom subdomain URL structure is ready to go .