Buying a gaming project according to the White Label scheme is the fastest, easiest, and most affordable way here. This solution includes the implementation of all technical aspects (a platform, a game library, well-thought-out design, a license, payment aggregators, hosting services, software, etc.).
The second option is a franchise agreement. You can get a ready-made website and profit from it. You just need to pay a commission fee for using the software. Such projects guarantee fast payback and high revenues.