If you have a single app on your server that will be using multiple subdomains, you will need a wildcard SSL certificate.
A wildcard SSL certificate typically costs more than a multi-domain certificate; however, if you have a dynamic app that will have an ever-growing number of subdomains, a wildcard certificate will likely be more cost efficient.
For example, one wildcard certificate for *.yoursamplestore.com will cover the following subdomains:
It will also cover any other subdomains you might continually add.
However, the naked domain yoursamplestore.com is not included by default by most certificate authorities. You must ask for it to be added as a separate SubjectAltName.
One option for a reasonably priced wildcard SSL certificate is the PositiveSSL Wildcard from Namecheap.
You don't need to do anything special to install a wildcard SSL certificate on your app.
First, generate an SSL key and certificate signing request (CSR) with a wildcard domain in ServerPilot using our basic guidelines.
Next, purchase a signed certificated from a Certificate Authority, providing them the CSR you generated in ServerPilot when they ask for it.
Then, when they send you the certificate, add that to your app in ServerPilot in the SSL Certificate field of your app's SSL tab.
If you want a wildcard SSL certificate to use on multiple apps that each have their own subdomain, copy the SSL key from the app where you generated the key and CSR used to buy your wildcard certificate.
Paste that key and your wildcard certificate into the SSL tab of each app you want to use the certificate.
Finally, delete the wildcard subdomain from the Domains field of the app used to generate the SSL key and CSR.