Add subdomain to whitelist

Hello,
I have domain jancejka.cz in whitelist.
Do You can add subdomain vps.jancejka.cz, where I test it?
Thanks.

In your letsencrypt beta invite mail, it says

Your whitelisted domains are:
[domain names]

These are the domains approved out of those you submitted. If you're 
missing domains, likely they weren't in your original submission, or 
they may have had a typo. If you like, you can re-submit to the beta program and you'll receive another notification when they, too, are whitelisted.

Basically, just submit the form again with vps.jancejka.cz

You may use the form below: