I am unable issuing SSL for Sub Domain with a hostname ?

Hi everyone, I have created panel.example.com with SSL selected. but I am unable to get working as a hostname.

Then I tried to issue SSL for the hostname panel.example.com but is not in the dropdown list to select.
Any help would be greatly appreciated.

Thanks

So, you want to add ssl in subdomain. am i right on this?

Regards,
Bobjection
ttrockstars

Dear Bobjection
I would like to make my hostname is my subdomain?
Regards
Alamili

Dear Bobjection
I would like to make my hostname my subdomain?
Regards
Alamili