WHMCS use an existing domain

Hey Guys,

I have a question about WHMCS and I know I have more chance to get a reply here than on the WHMCS forum.

So I was wondering if you ever used the “I will use my existing domain and update my nameservers” option.
I would be intressted to set it up for my clients so they can use our DNS.

But I have an issue with it, I litteraly don’t understand where the client should manage his domain names at this moment or know where to point.
I was thinking to do that on plesk first, but it’s really confusing because it means that if the client registred the domain at us, he can simply manage it on the client area. But if he didn’t registred/transered to us, then he can only manage it via Plesk, which at my taste is stupid as hell.

But if the domain doesn’t show up in the client area I can’t enable the DNS manager, is there a way that the clients can add a domain without paying for it, so that they see it in the client area and if they wish can manage there DNS?