When you create a new product in Clients and Billing, there is no payment link to allow customer to sign up directly. Considering how easy Stripe makes it to create a payment link, I am not sure why this is not a standard feature here.
If you bill directly with Stripe, you can create a payment link which you can share with customers, use on buttons, etc. For now, this is how I am doing it since it is the only option.
The downside to doing it this way, is that it keeps the billing separate so now I have to manage 2 billing platforms. It also means two different client portals.
Please make it possible to generate a payment link on ALL products, not just hosting, and make it possible to create a Hub account (via whitelabel hub client) when a customer buys these products.