From a software engineer's perspective, why don't you create a page somewhere on your website where the customer fills out several input fields which your HR documents require and then the customer submits the form once all the required fields are filled out. The form would then submit that information to your HR software or some sort of software which automatically creates the documents that you are selling.
This sounds like a software automation solution.
I've done similar automations before if you're interested in hiring help. But I've told you how you can do it above.
I hope it helps,