I’m having trouble setting up custom SSL certificate (wildcard certificate) for my static site. When I try to add it, I get an error.
Your custom SSL certificate covers example.com and *.example.com. You’ve chosen to setup abc.example.com, which is not covered by the certificate.
Hi @bone ! 
Unfortunately, we do not yet support wildcard certificates for application or static site hosting. For those, we only currently support adding specific, individual domains.
You would need a custom certificate that specifies the exact subdomain you’re attempting to use on the site.
I’ll add your name to our feature request for wildcard subdomains for application and static hosting.
If you need to secure all subdomains of example.com including abc.example. com then you need to buy wildcard ssl and while generating CSR you also need to mention *.example .com in the domain field after your domain and the subdomain will secure.
Try to purchase SSL on your own or I also know some providers. If you want then you can check here https:// certera .com/ssl-types/wildcard-ssl-certificates
Hello alpha_mann and welcome to the community
I wanted to note that although you could purchase a wildcard SSL certificate from a third party provider, you will not be able to install this successfully for a domain name used within Kinsta Static Site Hosting.