WHMCS also offers (one-time payment, but with annual support renewal) and leased licenses (monthly subscription). Every legitimate license must be purchased from WHMCS or a verified reseller like cPanel or hosting providers.
If the cost of WHMCS is too high, consider these legitimate alternatives that offer free tiers or lower costs: whmcs valid license key free updated
You don't need to risk your business with cracked software. There are official ways to get WHMCS at a lower cost: WHMCS also offers (one-time payment, but with annual