Yes, it is possible to set up wildcard subdomains.
You can add them by opening the root domain's details in your domain view. Click on "Details" and then navigate to the "Subdomains" tab.
Once there, click on the "Add Subdomain" button.
Into the subdomain field, enter * (asterisk) and follow the instructions shown in the subdomain adding form.
You can use wildcard subdomains with our shared hosting and custom hosting accounts.
Please remember that if you wish to install the Let's Encrypt SSL certificate for your wildcard subdomain, you must use private nameservers so that our DNS service can serve your domain's DNS zone.
If you have any questions, please contact our support team.