How to make a closed portal for clients?

Question

Work organization

It is necessary to make a website (and/or a private portal) for clients.
How it should look like:
1. There is a link: mysite.ru when going to the site, people see an authorization window, enter their login and password
2. Get into their personal account
3. The client can place an order for services, the most important thing is to have "History of operations"
4. Billing (payment) is not entirely interesting, if it is good, if not, it's okay, but having it as a mandatory issue is not yet a question
5. Some kind of help section, where it's just a description - I think this is not a problem in any system
6. Feedback from the admins, on any issues
In principle, something like this, I just don't know how and on what to implement it.
PS Yesterday I was advised WHMCS, in principle, a good system, but that's just, maybe someone will explain whether it is possible to close the client part from everyone at all? That at transition there was an authorization form.

Answer 1

Billmgr from ispsystems will suit you.
It is made for a slightly different purpose, of course, but you can add services with any name there (and it’s convenient to bill them), so it more than fits your description. There is also payment (with everything your heart desires), but without legal. faces, not all methods can be activated.
There is support inside.
There is also a "Knowledge Base" module hidden behind authorization, of course.
For unauthorized people, it looks like this - https://my.ispsystem.com/manager/billmgr and nothing else -) Well, unless you remake this form yourself, as you need.