Blank domain name while make new order

[Hosted.pw]

Hello. I have successfully installed and configured Blesta. I very like it. Trying to customize it for my purposes, all be fine. But have a one small problem.

If I left an empty string in domain name while make a new order - I got a blank page after form submission. Is there are a way to generate somehow a "free" subdomain name for client? I want to generate a subdomain for my "system" domain. Maybe there are some module or plugin? If no one, where I can get started in writing own module or plugin, I am a PHP developer so this is not a problem for me. But at first, maybe someone know about already existing module or plugin.

[Paul]

Are you trying to sell subdomain hosting off of your own domain? What module are you using? See this request for cPanel https://requests.blesta.com/topic/choosing-a-subdomain-for-hosting-product

To accomplish this now, you'd need to make a tweak to the module.

[Hosted.pw]

I am using a Vesta module. I dont want to sell a subdomains I want to give free one. As I have found, Vesta Module adds a domain field to configure while creating a new order... So I want to add a "default" value to this field if no one is entered, but now the problem is that internal user id is not available in code, while configuring the order... Seems it's will be available only after last order step.