As MahGah says. You need to purchase the license through a CSP partner. But that does not mean you have to involve that partner in your implementation. If you chose to all the implementation yourself you can do that.
You only need the partner for the actual purchase of the license, though in most cases it is recommended to have some assistance from your partner.
But we have some cases where the customer have such good knowledge about the product in house that all we provide is the license.
