When you create a custom domain through FormAssembly, the SSL certificate for that domain is something that your organization will have to purchase. Currently, we only provide the SSL certificate for your original domain and that certificate cannot be shared with other domains for your instances.
When purchasing your SSL certificate, it should be in the Apache .pem format.
Additionally, you will need to send over the private key in order to configure your instance. Please contact our support team to send this information.
For information on upgrading, please contact our Sales Department at firstname.lastname@example.org.