We are a frontend builder platform and we generate React Next.js code for each of our customers. We need to build and deploy it with our custom subdomain, like web1.ourapp.com, web2.ourapp.com, for each customer. Can Vercel handle this PaaS side? We only send the repository code in zip or S3 uploaded format, and Vercel will deploy it and allocate SSL certification. After that, we will point the domain to vercel host. All things will be made automatically, so you have to provide an API. If so which service or package can do tihs?