No. Any repository claiming this will either be abandoned, contain malware, or be removed by GitHub for DMCA violations within days.
Use the official 15-day trial from WHMCS. It is safe, legal, and fully featured. After it expires, export your data to another platform or buy a license.
A billing system is the heart of your company. Using a cracked license puts your reputation and your customers' data at extreme risk. It is always better to use a free open-source tool than a pirated "premium" one. To help you find the best path forward, could you tell me:
